I think this is why I might raise an eyebrow over the 5E bard. Mechanically, it's a rough 'n tough class, capable of great things. I'm not fond of it being 9th level/full caster, but hey, if we subscribe to, 'music is magic!' then powerful music should be on par with powerful magic. Personally I'd want to bring the bard back to a more 'jack of all trades' - the wandering vagabond who dabbles here and there and brings a wide spectrum of assorted (rather than specialised) talents together into a cohesive whole. Valor Bard does bring a bit more fighty into the mix but then again, even they are getting Power Word: Kill, True Polymorph and potentially Wish, in time. But hey - if folks are happy with the bard being a 'musical mage' on par with wizards and clerics in terms of sheer magical power, then to each their own.
I vaguely recall that part of problem that the 5e designers faced was that the bard's jack-of-all-trades niche did not necessarily work as intended, particularly when it came to spellcasting. In at least the core PHB of 3e, the bard was the sole 2/3 caster, sitting above the 1/4 casters (e.g. paladins, rangers), but below the full casters (e.g. wizards, clerics, druids, sorcerers). In 5e, the 3e 1/4 casters got upgraded to 1/2 casters, which placed the bard into something of an awkward position. Were bards more appropriate as half-casters or full-casters? To be honest, I can see the potential argument for either.
I'm not saying the Bard doesn't have knowledge. However it is, like you said, presented as less of a historian/lorekeeper and more of an entertainer/musician in the default portrayal.
Hopefully you realize that these aren't even remotely exclusive ideas, right? Again, if we look at lot of the flavor-fluff of the bard, it remembers these tales and stories, epics and sagas, poems and songs, and the like because these are regarded as snippets of lore and history. That's even a HUGE aspect of what the bard was. Being a historian/lorekeeper (and occasionally other functions, such as law) and a musician were practically inseparable! There is even a sense that they are not learning these things to entertain, but, rather, they entertain because they have learned an overlapping set of skills.
And while they do have "colleges", the more common (overwhelmingly so) portrayal has them picking up their skills and knowledge in their travels as opposed to study in a formal institution with a fixed curriculum. Sitting in a hall and studying tomes and listening to lectures is certainly more in line with how D&D presents the training of wizards and clerics. I suspect a lot of this is a hold over from 3e, when the the Bard became a spontaneous caster with chaotic leanings- not very conducive to portrayal of an especially academic/studious character. More like your stereotypical artsy theater school student than anything.
Really? So the fact that bards are said to "enter long-forgotten tombs, discover lost works of magic, decipher old tomes" means nothing to you? Or nothing that the Creating a Bard even asks whether you attended "a college where you studied bardic lore and practiced your musical magic?" Or that the Lore bards spend their time "collecting bits of knowledge from sources as diverse as scholarly tomes and peasant tales" and "gather in libraries and sometimes in actual colleges, complete with classrooms and dormitories, to share their lore with one another"? Apart from Harry Potter and the Wizards of Earthsea, a lot of popular depictions of wizards veer away from "wizarding school." D&D tends to depict wizards as a solitary, keep-to-themselves sort who seclude themselves in their towers. And there is a less a sense that they are driven by a desire to "accumulate knowledge," but, rather, that they desire to "master magic."
I don't mean capital d Divination as in the "part of the Divination spell school" sense. I meant in the "seer/fortuneteller/advisor" sense. Just look at your comparison between the selection of Bard and Cleric divination spells. The Bard list stands out in it's access to all the spells that facilitate speech, personal connections, and generally highlight the Bard's social skills and role as an entertainer. The Cleric's array of divination spells involve a lot more actual divining and actually knowing stuff.
It seems as if you are conflating two differing senses of "knowing stuff" then. I don't know if you are trying to have your cake and it too or what. You say you mean "knowing stuff" in the "seer/fortuneteller/advisor" sense, but when I look at what you describe, it is essentially the difference of three spells and a cantrip: Guidance, Divination, Commune, and Augury. These are also unique divination spells that even the divination wizard lacks. I guess the divination wizard isn't meant to "know stuff" or be a "seer/fortuneteller/advisor" either. But it's worth noting that both Divination and Commune are spells
explicitly tied to "knowing stuff" through a deity or a divine proxy. This is not some rote fortune-telling and magic crystal balls we're talking about here. This is the sort of activity that belong to priests, shamans, and spiritual advisors. (Though it is certainly strange that a cleric seer/fortuneteller could not Identify, See Invisibility, or have lack Foresight.) And the bard's list of communication divination spells that make them "stand out" from the cleric amount to a whopping magnitude of two spells: Speak with Animals and Comprehend Languages. That's it, unless you count Detect Thoughts. A cleric has Tongues too.
The bard's "knowing stuff," however, pertains more to "lore/knowledge/information." Unlike the cleric, the bard has access to the spells Identify, Detect Thoughts, Locate Animals or Plants, and Foresight. How does that not constitute "knowing stuff"? How does Detect Thoughts, See Invisibility, Scrying, and Foresight not help the bard with the seer/fortuneteller/advisor sense of "knowing stuff"? How does True Strike, Detect Magic, Identify, See Invisibility, Locate Animals or Plants, or Foresight highlight the bard's social skills or role as an entertainer? Actually for that matter, what divination spells do you see on the bard's spell list make him an entertainer? You are clearly seeing something that I'm not there.
Most works that have Bard-like classes but ditch the instruments and usually have art of the character speaking, gesturing, reading/studying/writing, teaching, pondering.
Like the bard on page 55 of the 5E PHB?