I think the platforming zeitgeist has shifted to 2D.
Metroid Dread, Hollow Knight, Mario Wonder, Shovel Knight.
But 3D platforming is still alive as a genre.
Mario Odyssey, Sonic Frontiers, Yooka-Laylee.
And the remake scene for 3D is popping off right now.
Crash, Spyro, Ratchet, Mario 3D All Stars, Metroid Prime Remastered.
Specifically for the subgenre of 3D third-person platform-shooters, check out Splatoon 3. For 3D first-person open-world platform-shooters, Metroid Prime 4 is in development.
But for “3D open world third-person platform-shooter,” that genre is essentially Ratchet & Clank. But these days I think Insomniac is busy with Spider-Man. You can maybe count Jak in there, but Naughty Dog hasn’t touched that franchise in ages.
I think the take away is that each franchise has it’s own niche. What you’ve described is so specific that you’re really just talking about Ratchet. Open your requirements a bit more, and you’ll find plenty of great, new platforming experiences.
Also, if you think there’s untapped potential, I encourage you to make something! Unity is actually pretty easy to use.