I just think it looks ugly, TBH. YouTube’s implementation isn’t the worst I’ve seen, like sometimes on the news they show vertical phone video and fill the screen with something similar but with less of a blur and it’s really distracting. YouTube’s isn’t as bad, but I just don’t think it looks good. Glad there’s an option though as clearly some people do!
In my case the Deck (OLED) has one major advantage over my PC besides the portability - its screen. My PC screen is a perfectly competent 1440p panel with decent colours, but it’s also a 60Hz IPS. Some games the power of the PC (5900X, 3070) is going to make games look better on there, others the Deck’s OLED is going to give it the win. Or there’s always streaming to get both!