That's what prompted this thread. I was thinking about what came next and decided that just "more" was boring. We've have lots of content, and I doubt the majority of gamers have used what we have. "More" didn't interest me.,
I've used a fraction of the monsters I already own. More are almost wasteful. That's when you transition from necessary content to bloat. From requested and needed content, to content for the sake of producing books.
One of 5e's strengths is that (compared to previous editions) a higher proportion of the character options are viable, useful, and/or interesting. But it's still not 100%. Some options simply see more play, whether that's because they are mechanically stronger, more useful for expressing (or making viable) a wide range of concepts, or simply fun in their own right.
As an example, consider the Cleric class. It's a strong class. But a substantial portion of its mechanical strength comes from a small handful of popular spells like
Spiritual Weapon and
Spirit Guardians. There are a
lot more Cleric spells to choose from, but for those Cleric players who value the mechanical strength of their choices, the range of viable choices is much more limited.
As another example, consider the popular Warlock dip. Thanks to
Eldritch Blast, cantrip scaling, and the Agonizing Blast invocation,
any character with at least two levels of Warlock and halfway-decent CHA can pull their weight in combat for the rest of their career. This frees up the entire rest of the build to pick character-concept-expressing abilities without regard to combat strength. This makes a Warlock dip extremely attractive to players who want to focus on non-combat abilities. (Of course, the Warlock dip can also be used purely for its mechanical strength, so it's also popular for the same reason as the top-flight cleric spells in the previous example.)
I suspect that the oft-expressed desire for "more" character options is more-precisely a desire for more options that offer compelling alternatives to the most-popular options available in the existing content. In other words, it's not that there aren't enough options already, it's that (under a variety of subjective standards used by some fraction of the player base) there are too few
appealing options.
Unfortunately, the reality of dead-trees publishing makes it extremely costly in customer goodwill to modify already-published options to make them more appealing. Thus, addressing the desire of some fraction of the player base for a larger number of appealing options requires publishing more options, some fraction of which are appealing. Alas, this leads to bloat (and, arguably, power creep, especially if a higher proportion of the new content is appealing).
It may well be that the players asking for new player options don't see a need for a greater number of appealing options than you do. Instead, because everyone has their own subjective standards, they may simply consider fewer of the existing options to be appealing, and thus aren't satisfied by the current content.