Why do freetube and new pipe break at different moments in time ? Iirc, it first started for new pipe, then for a little while with pipepipe, and it's freetubes turn.
Google clearly has the ability to break any and all third party client at any time.
My theory is that they're conducting random campaigns of working-but-not-all-the-time on this or that client at different times to grind everybody down and force them to comply through shear exhaustion. Because if they banned all 3rd party client outright, it would negatively impact the antitrust case against them.
Because alternative clients offer features that only the for-pay official client offers, like subscriptions and playlists, and Google can't collect data on what people subscribe to or their playlists because in alternative clients, they're stored locally.
Google doesn't hate third-party clients because they skip ads: it hates them because they impede surveillance and privacy invasion, which is the true bread and butter of Google.