I can wash and clean my car no problem.
But correcting something like this is beyond what I'm willing to tackle.

To This:

Actual reflection from passenger side front door after 2 stage correction.
I can appreciate the skill involved for proper paint correction.
You also have to look at the lost opportunity cost of your time.
If you can earn more than the charge of a detailer in the time it takes to complete - you are ahead.
Even if I could learn to do a two stage paint correction - it would be many many hours, and I would still probably take 3 times as long as a pro and most likely not get similar results.
For outside paint correction? Detailer for sure.
When you wash, strip, clay, wash, dry, polish, glaze, lsp/wax the hours start to add up quickly.
I generate more enjoyment for actually driving my car than polishing it.
Jet Black is awesome for about 2 weeks after a paint correction!