I know there's still a significant following for them. But there's really not many companies developing 3D Platformers anymore built for modern gen consoles. Which is a shame since it's possibly my favourite video game genre.
Of course, Nintendo still keeps the genre alive to some degree. But that's just Nintendo. Other than that we've been seeing remakes for Crash & Spryo. (I didn't play Yooka-Laylee. A Hat in Time was excellent though. But, nothing new as far as I'm aware of. Apart from your occasional Kickstarter Project that may or may not get the green light. Also, a lot of the time the games that do get released only a handful of them are ACTUALLY GOOD. Some come with a lot of problems. (The Last Tinker: City of Colors for example.)
I know a lot of people these days arguably play video games for more "immersion and realism" but I just really miss the 3D Platformer genre in general. In my opinion, it is hard to make a good 3D Platfomer. Especially, these days when there's little demand for them.
Many might say "Oh, leave them in the past. They were for the N64-PS2 era." That's true. But at the same time we all grew up with a 3D Platformer that we adored.