Actually he would get paid much more. The NBA CBA has a "max contract" capped at 25% of the salary cap[1]. There are numerous players playing on essentially the same deal, even though there is clearly a big gap in talent. If you look at the list of salaries for the 21-22 season[2], Steph Curry is the highest paid player at $45.6M, which is only about 15% higher than the 10th highest paid player despite being significantly better.

[1] there are some other contract terms that allow for up to 35%, but those require a bunch of other non performance conditions to be met. [2] http://www.espn.com/nba/salaries

Thats a good point, and I think in general I think using professional sports as an example either for or against unions is a bad faith argument because of the unique dynamics present.