I was a C++ developer in a past life and Cmake was a big reason I moved on to greener pastures. It’s the only language that is more toilsome to use than C++ itself, and that by an enormous margin. It’s stringly typed (no, that’s not a typo, everything is a string), it’s syntax is obscure, it extends so poorly that it just bakes-in support for building popular libraries (e.g., Google’s test framework, Qt, etc iirc), imports are implicit so it’s tedious to track down the definition for a particular symbol, it completely punts on package management—not only were builds not reproducible but you couldn’t even get it to download and install dependencies for you from a declarative list. Cmake isn’t a build system, it’s a toolkit for scripting your own bespoke build system (and a crumby one at that) which basically means that every project is a unique snowflake with its own distinct quirks which are tedious to learn and maintain—even though 99% of projects would be covered by something like cargo. Those are some of the things I remember off the top of my head ten years later (it was also doggedly slow and things would break across minor releases, but I’m told those things have improved).

Cargo is imperfect, but it’s the right tool for the job 99% of the time.