The RPi 5 SoC does not have VP9 hardware decoding which is necessary for YouTube videos. Anything above 1080p30 inside a window will suck.
Weird part is that RPi4 SoC has it.
Edit: confirmed by Raspberry Pi Foundation themselves, only hardware video decoder is HEVC.
What’s really interesting is that study was made and the distribution of social drinkers, nice drunks, mean drunks, etc, roughly matches that of the humans.