I feel like I agree with Tonug a lot, however I believe that I do feel a tiny bit more comfortable playing the ryona out myself (usually as the victim, even more so since I have actually played the victim in other people's Tekken 7 videos lately... and, well, my universal bad luck trying to play others online on my own channel). Watching videos can have a convenience factor (like the video has camera hacks or very good video and sound editing to expand on the scene) and, again, be close to how you'd imagine your favorite girl being in a hopeless or humiliating ryona situation that you probably never would've seen on your own power, but often times than not, there may be some things featured that aren't your cup of tea. Usually for me, it's either the clothes that girl's wearing (most game videos just love putting them in bikinis and such, for example, but for me I've never liked them that much and prefer casual or fashionable wear) or the attacker is the same as a lot of other like-minded videos with little variety, or the editing is very lazy and it takes away from the video as a whole.
I suppose it's a complete immersion thing. When its me playing... and losing... that's just exactly it. That's ME, losing. Like in Tekken, that's my Xiaoyu or Lili, wearing my own tastes of outfits that I love and prefer, moving as I would try to move, attack, and ultimately win a fight with her, being dominated and humiliated by said King, Dragunov, Nina, Chloe.... heck, ideally even another Xiaoyu or Lili in my own preferred tastes. And when I lose it's usually overwhelmingly bad, so that just adds to the fact that I was just that powerless to prevent that opponent from having their way with my favorite character and turning her into their plaything. I do admit that while I don't mind and enjoy losing as long as its a close battle, I get really embarrassed if I wind up losing in a landslide victory in my gameplay channel videos. It may be set as a typical gameplay video since I no longer edit but to me, that's when that ryona side kicks in. It's a sinking feeling when I get beaten by someone that's just that much better than me... or by someone I know I understand the game better than them but for some reason I just kept letting my guard down at all the wrong times, and I often feel that feeling translates to the girl I'm playing as also feeling that exact same way. It's more 'personal', so to speak, so it makes watching that happen 'stronger', I suppose.
Ultimately, when you watch other ryona videos, while that's nice, it's still not quite MY experience or preference with ryona; just observing and hopefully enjoying other peoples takes, but when you play it out and it happens to YOU while you're playing as said ryona victim (or, to others, as the attacker), well... that's a completely different feeling, and it tends to be a greater feeling... (pictures are a 'case in point', from my latest gameplay video on Youtube.)