While I mostly keep watching the show out of some kind of morbid fascination, I've always believed that Rick literally is Morty in some way, or at least that was the originally intended big reveal.

It's just too on brand for the shows sense of humor, and at least in the first season they were really into deconstructing or mocking a lot of classic Sci Fi tropes that while not that well known to the average viewer, any Sci Fi nerd would instantly recognize (in other words, Futurama but with dick jokes), and what fits better into that mold than the Grandfather Paradox?

When I have mentioned this, a few people have said that Rick "refuses to do time travel" or similar, but again what is more on brand for the show than for Rick to just go "Haha fuck you, I always knew how to time travel, but I don't do it because reasons!" or some similar reversal. I mean they spent the first season loudly saying they weren't a serialized story, while dropping breadcrumbs about a grand serialized story.

Apparently the recent anime crossover semi-confirms this theory, but I can't be arsed to watch it, and I don't think it is canon anyways (or if it is, it's from dimension D-414 or something).