I kinda like dice pool systems, but can get why some people are turned off by it.
I almost always did some form of this for chargen. Like in AD&D you'd pick your class first, and get a pool of 6d6 for your main stat and 4 or 5 for the rest. And even then if you got a really shitty main stat roll I'd throw it out and so you'd nearly be guaranteed 16-18 in your main stat.
I was seriously not into having a retarded mage or a "fighter" who couldn't lift a toothpick.
For all the percentile cucks, I'm just going to say that D20 is percentile just gated at 5% increments. If you really care about +-4% ...fucking lol.
D20 does fine for "roll to hit a thing." I like a little more granularity for other things, though. "Roll to hack the Pentagon using quantum electrodynamics" for instance.
CoC your character never levels up, they slowly erode until they die, go insane, or both.
While that's definitely true, the irony is they get more and more powerful while doing this. Since there's no method of restoring sanity, and you're inevitably going to die, the most powerful characters are those about to do either of those things, and they've probably been collecting the very eldritch lore (and spells) that have driven them to the verge of insanity.
One of my favorite (sadistic) mechanics is I had an insanity system for what someone would do when they went utterly insane and turned into an NPC, and one of the big ones was casting one of those spells there was no practical use for, like summoning some uncontrollable entity.
(Hence excessively powerful PCs often voluntarily resigned to NPC status in a calm, peaceful asylum somewhere to avoid any further sanity loss.)
I always considered Call Azathoth basically a world-ender. That was cast by an ostensibly "sane" character, though, when the end of the world was already nigh, to basically nuke the location the already doomed party was at, having lost the end of the world scenario already. So the world got ended by Azathoth instead of the already-existing world-ender.