I didnt say that i allways use my instance, i use some of the public ones too with very few being slow due to many people using them. If one doesn’t work try another.
The underlying issue is youtube rate limiting the video proxy, so if the instance is trying to play 10 videos at once it will get ratelimited.
The solution to such problem is either complicated or simple. The simple one is try to convince your favorite creators to use other platform then youtube for example peertube, Odysee or rumbl.