I spent a decade in a similar paid field and while pay was tied to position there was no real way besides time to figure out position. Junior dev vs senior dev is often a matter of time and not ability.

im not sure. in a perfect society if the junior dev is better and works harder and bring more value to the company he should be better paid than his senior. it is capitalism and if a company is judget by its output an employee should too

If the other dev can’t perform better than a junior dev, they shouldn’t be a senior dev. There’s no reason that you have to go up in the titles over time if you can’t improve your capabilities. Titles should reflect skill, not just be handed out due to age.

If he's better and brings in more value, he'llbecome a SR dev quickly.

so 1 senior dev = 1 senior dev? you're surely thinking same for a doctor right? and you will trust with your life a guy who studied less and got 10/20 at all his exams all his life and went party while the other one was practising surgeries?