With Reddit shutting down its API setting a precedent in the corporate tech world (and Reddit was a major outlier in that a ton of their users are technical minded and support third party clients, YouTube does not have that kind of userbase and will not get backlash for it), Twitter doing whatever the fuck they’re doing, and Google already hellbent on destroying ad blockers, the days of Newpipe, Invidious, and Freetube are numbered. Wouldn’t be surprised if they implement Netflix level DRM tomorrow that makes alt clients impossible. I say savour your alt clients while you can guys, you won’t be able to soon.
My understanding was that these programs don’t rely on YouTube’s API, but rather they are loading the page and scraping it for the relevant video files, comments, and other data. So it’s a little harder to kill them than just shutting down API access. That said, with all the new web DRM crap getting pushed by Google and others, I can’t imagine it will be long before they can detect that you aren’t viewing the page the way they want you to view the page, and then block access in some other form.