NewPipe has been working for me for years with occasional breaking changes on YouTube's side that required an urgent update. I watch pretty much everything at 2x speed 1080p and have no issues with buffering.
I generally watch things on 720p, and it's been crashing frequently. Setting the resolution to 1080 usually solves the problem, but transfers the problem to my wonky internet connection.
Or if it does work, its absurdly slow.