My cousins who are in their late 20s probably spend more time watching playthroughs than playing the games themselves. I think part of it is they simply can’t afford to buy all the games they want to play. Another part is some games are just a good story that can actually be viewed and experienced through a playthrough.
Personally, if the game is easily available to me, I’d prefer to just play it.
I’m so glad I started the series from Trails in the Sky 1. I’m currently on Cold Steel 2 and it’s been a great time.