There is a non trivial relationship between colleges and businesses, so you are likely to do many problems in college that are not terribly different from the interview questions. Additionally all of your peers have been interviewed/do interviews/do referrals and that does matter.
College students generally did not do incredibly well on practical problems, so I would expect a non college candidate to do really well on them.
Many of the best co-workers that I remember had physics degrees. In fact, it was so pronounced I personally consider a physics degree to be a top tier signal of programming ability, but that's my own personal prejudice.
If your degree isn't from a top 10-20 CS school it's probably not worth it if you have experience. If you can't make friends while doing the courses, then I don't think it's worth it. Going to a good college is much much much much more than a few lectures, some book reading, and some assignments. It is face to face time with world class experts, it's a culture, it's social, it's exploratory. You can potentially work on bleeding edge research or be introduced to things you never knew existed.
It sounds like your idea of what college is, is that it's a technical education rather than a liberal education. If that's true I think your perception of college is wrong.
There are some situations where a college degree really matters. If you want to apply for a work visa in a foreign country, a degree from a good college can potentially get your application a rubber stamp or lack of one could completely restrict you from it.