instead of you telling the employer that they have to prove their value or the deal is off.
What?
Performance review is from the employers side, obviously.
There is nothing stopping from you to walking into your boss' office and telling them that you're not getting paid enough for the work you do. Then either they pay you more or don't and you find a better job.
You should tell that to everyone using electric bikes during the winter due to it easing biking a ton during winter.