RSS is alive and well if you want it to be. I've switched to theoldreader.com when Google pulled the plug, imported my feeds and have been there ever since.
I'm subscribed to 125 feeds, 72% of which had new posts in the last year (following super low volume things is one of the many advantages of RSS). Most of the inactive ones have simply atrophied or ceased to exist entirely rather than turn off their RSS feeds.
I never log into YouTube but follow many channels via RSS instead. There's also Twitter gateways, although the one I've used stopped working and most everyone I care about has moved on to Mastodon anyways, so I haven't bothered with finding another.
I still regularly subscribe to new blogs, Youtube channels and other stuff via RSS and don't really know any other sane way to follow such things. I'll certainly not go and bookmark a bunch of sites and then click on them to see if they have posted something new or not - that would be insanity.
So yes, Google took a big dump on RSS, but then that's what Bigcorp does. Get on with it - RSS is fine. Build more feeds into your webthings because if it doesn't have RSS the grumpy old nerds like me will probably not look at it twice! :-P