I've landed on numerous Cloudflare pages that told me a site was down and the problem was on their end.

Not once has one requested that I enable JS. And why would I? It's not their page I want to see in the first place and I'm getting the message fine without enabling JS.

And why would you? Then wonder whether you being "suspicious my computer is compromised" is a valid concern or not. I can't say if it is or not.

I can say if it wasn't before it probably would be now if it was a page that got you to enable JS for it.

That's all you have to do for a drive-by download from a malicious script driven ad. Just land on the site with JS enabled for it. It will do the rest and be at work before you know it. Or start to wonder about it.

If it was me, and it is not, I would reboot it now, have my installation media of choice ready at boot, wipe it clean, rebuild the System from scratch and forget about everything that is on it. If it hurts don't fret too much.

That's mostly your brain taking in new knowledge and learning not to do that again. It's supposed to hurt so you remember it and don't make the same mistake again.