I’ve found myself thinking similar thoughts (as OP) at a startup I joined. It seemed like no one valued code quality, yada yada.

If the things you value are valuable in your new environment, you’ll find the tact, time, and patience to improve the codebase.

One thing that helped me was helping others. Writing documentation, documenting processes, playing dumb sometimes...

Your standards are _not_ unreasonable, but they are _your standards_. If you want others to adopt them, you must lower the cost for them to do so—and must do so in a genuine way.

Lately, I’ve found the quickest way to be “right” is to allow others to be “wrong.”