It's not dying out. Nintendo brought it back to the forefront. That's why the Switch has been outselling every other console. Look at all the celebrities that have been promoting local co-op
Never liked split screen as a kid and still don't like it as an adult. The only local co op I do is the odd time I'm at my buddy's place and we decid to play some beat em up or fighting game. Honestly I'm fine with that. We are both in our early 30s and not trying to always be at each others place all the time to play videogames. Playing online with a headset is good enough for us.
Not knocking people that want split screen co op but that's a feature that is dying out due to how performance reliant games have become.
switchset: search results - flair:Star