I haven't watched much with Sims 4, and even what I saw with Sims 2 was limited. That's when I first started watching. Even then, I mostly exclusively watched one creator and any music videos I knew. The only thing I've seen since TS2 is Remi Marocelli's Bella Goth series, and that's because it's a quality, well thought out production that gave me a solution to the Bella Goth conspiracy. Iremember trying to find more machinima to watch back in the day, but it was hard. Between music getting copyrighted left and right and the juvenile storylines, I just gave up.
Copyright killed music videos, which was a shame, there were many good ones, and they weren't trying to steal anything. Age may have something to do with it too; whether or not there was more machinima during TS2 era than 3&4 I can't say, because I haven't been watching. But I was much younger watching TS2 machinima, and easier to satisfy in terms of what was a good story, characters, etc.
Edit: others have mentioned cc, alpha cc in particular, as something that takes away from the experience, and I have to agree. It was something I didn't mind on ts2, but the styles seemed to mesh a little more. It's so jarring in 4. If YouTubers of any sort use alpha cc I am less likely to watch videos, and that includes machinima
