Adjustment layers / nondestructive editing, text and shape effects are huge productivity boosters. It's a pain going back to a world where they don't exist - and many hours of paid labor for the employer, or taken out of your life. Missing CYMK made GIMP a non-starter for people working in print. A nice healing tool exists, but it's a pain to install as it is a plugin, even on Linux I had to hunt for dependencies from different repos.
How "basic" are these is debatable though. They are very useful, and widely used, and multiple image tools support them, that's for sure.