UngeheuerLich
Legend
Have you read the 5e PHB's description of the Bard class? "Magical Muse" is a pretty apt summarization of what WotC felt best described the class when they were designing it for this edition. They're magical minstrels and poets that draw magic from their music and stories.
The description text pretty clearly illustrates that the 5e Bard is supposed to be a magical muse. Every example bard character given at the beginning of the class description is described as singing, humming, or playing an instrument, the "Music and Magic" section pretty clearly supports this position, as does the Learning from Experience section.
Being a "muse" is built into 5e's concept of the class. I don't know if that is accurate for all of the previous editions' versions of the class, but it is for 5e.
That's not supported in the fluff text and only supported in two of the class's mechanics (Jack of All Trades and Magical Secrets). "Magical Muse" is supported in all of the fluff text, Song of Rest, Countercharm, Bard's being able to use musical instruments as their spellcasting focuses, and quite a few spells.
Not as well as literally every other class in the game. Lots of classes' subclass abilities are frontloaded. However, not a single other class only gets subclass features at 3 levels.
Again, the Bard is that class. It's supported in the fluff text of not only the core class but also plenty of subclasses (Creation, Glamour, Eloquence, Spirits, Lore, etc) and it's supported by the mechanics. If the class wasn't supposed to be a "magical muse", it wouldn't have been written that way.
Then the easiest solution is changing the flavor text, because after all that is not what the class crunch tells us (except for the 3 instruments they gain at level 1). Subclasses of splat books actually have more musical abilities, but in the PHB both subclasses support the Idea of a loremaster/rogue or warrior/leader.
It is also not what I have seen in play for the last few decades... the bard was never the muse. They did perform on stage sometimes, but their roguish behaviour and their magical one always stood in the foreground.
In ADnD they were correctly classified as rogues. The 3e bard was more musical I admit, but 5e puts them back were they belong.
I am not totally against changes. But relegating them to half-casters and adding musical abilities to compensate is the wrong way.
As others have already suggested, the warlock model could have worked well for the bard. Imstead of invocations they could have learnt bardic secrets that could be magical, musical or skillbased.
They would have to do more stuff than just casting spells during an encounter, but their highest spells are still (nearly as) powerful as other spellcaster's.