e.g. By using a cryptography library / algorithm someone else has written, I don't need to think about it (although someone has done the thinking, I hope!). Or by using a high level language, I don't need to think about how to write assembly / machine code.

Or with a tool like a spell-checker: since it checks the document, you don't have to worry about spelling mistakes.

What upsets is the imbalance between "tasks which previously required some thought/effort can now be done effortlessly". -- Stuff like "write out a document" used to signal effort had been put into it.

In my opinion it's entirely comparable to anything else that augments human capability. Is it a good thing that I can drive somewhere instead of walking? It can be. If driving 50 miles means I get there in an hour instead of two days, it can be a good thing, even though it could also be a bad thing if I replace all walking with driving. It just expands my horizon in the sense that I can now reach places I otherwise couldn't reasonably reach.

Why can't it be the same with thinking? If the machine does some thinking for me, it can be helpful. That doesn't mean I should delegate all thinking to the machine.

Those are all things many people outsource their thinking to other people with.