1. All else equal, and looking at the industry as a whole, having a college degree in CS is an advantage in getting hired over being self-taught. Things get more fuzzy if your degree is in math/physics/etc., but those still confer some advantage.
2. The advantage is very large for entry-level roles but diminishes greatly with experience. The advantage is even larger if you went to an elite school. The advantage is small if the school is mediocre, and negative if it's a diploma mill.
3. The advantage varies greatly with the company. Google definitely cares more than most startups.
4. The advantage virtually goes to 0 within a decade but never completely goes away, simply because of effects like your-interviewer-went-to-the-same-school, alumni networks, and the fact that more people irrationally care about CS degrees in senior devs than are irrationally biased against them.
5. Whether the advantage is worth the cost is a very complicated issue. This advantage is almost certainly not worth it if you have to go 100-250k in debt (private schools). The opportunity cost is also quite large, but this is complicated because what self-taught job you get depends on your own background. Coding bootcamps also complicate things. At a certain point depending on scholarships / parents paying / going to an in-state school, it makes sense.