No. If you follow the letter of the contract, most IP assignments claim everything their employees do, but practically, that's just because it's impossible to write a contract that says "everything you do for your job, nothing that you don't".

The primary driver is that you don't want to get into litigating how much time your salaried employees work. So most employers will tacitly ignore side projects, only coming after devs who write code that steals users or shifts revenue from their customers to a project that a dev claims to own. And that's pretty rare.