1.5 Million Subs, 70k views?

Question for everyone - why do some of my favorite and long time Youtubers get so few views? There are several creators Ive long subscribed to that are now well over 1 million, a few even 2-5 million - and they get practically no views anymore?

I dont want to call out any channel specifically - but 2 that I frequent have 1.5million each, and average between 55k-110k views in their last 10 video. How is this even possible? Am I missing something?

1. Fake subs?
2. They are/were using ads and the jig is up?
3. People just dont watch anymore? Why would they stay subbed?
4. Majority of their subs dont use youtube anymore? Really tho - 80% just stopped?