CMake has become the defacto standard in many ways, but I don't think it's that easy to deal with. There's often some custom support code in a project (just as with make files) that you need to learn the intricacies of, and also external 3pp modules that solve particular integration issues with building software that you also need to learn.

For me, base CMake is pretty easy by now, but I'd rather troubleshoot a makefile than some obscure 3pp CMake module that doesn't do what I want. Plain old makefiles are very hackable for better or worse [1]. It's easy to solve problems with make (in bespoke ways), and at the same time this is the big issue, causing lots of custom solutions of varying correctness.

[1]: Make is easy the same way C is easy.

I didn't say "easy to deal with", I said it's not bespoke nonsense, and that you could keep it mostly unchanged today, 8 years later.

Plus - the "obscure third party modules" have been getting less obscure and more standard-ish. In 2017 it was already not bad, today it's better.