I used to love C++, template wrangling :-P aah, but pretty much gave up after C++11. Right about the time when Scott Meyers also said: "enough" (paraphrasing).

My biggest issue for giving up was the ever growing list of "don't"-s, its not fun to write in language where the design is so "loose" that to get reasonably correct/predictable code you always have to reference the list of "don't"-s.

And then having been a build maintainer on various projects the build and package management was a nightmare. Still vividly remember the first time I looked at Rust's cargo - mind blown :-)