Hat in Time is probably the last big indie 3d platformer, but I'd say Kirby and the Forgotten Land is a decent 3d platformer, unless you meant collectathon style 3d platformer a la what Rare made on the N64 etc. since you mentioned Hat.

I assume you've played or heard of Yooka-Laylee. There's also Clive n Wrench. Neither of those are great though.

I haven't heard of Koa before, but it looks interesting. I'll have to check it out.

But I really want a new Banjo game, however I doubt that ever happens at this point. I recently started working on my own Banjo clone in the Godot game engine because I don't see anyone making the kind of game I'm looking for.

There definitely is a lack of actually good ones in the modern era. Poi and Grow Home are some good ones you may not have heard of.