Don't trust the first google hits, especially if you are in the US. Disinformation by union busters is very common around here.
https://en.wikipedia.org/wiki/NBA_salary_cap#Individual_cont...
"The maximum player salary is based on the number of years that player has played and the total of the salary cap. The maximum salary of a player with 6 or fewer years of experience is either $25,500,000 or 25% of the total salary cap (projected for 2017–18), whichever is greater. For a player with 7–9 years of experience, the maximum is $30,600,000 or 30% of the cap, and for a player with 10+ years of experience, the maximum is $35,700,000 or 35% of the cap.[19][33] There is an exception to this rule: a player is able to sign a contract for 105% of his previous contract, even if the new contract is higher than the league limit.[34]"
If anything, the tech industry should be leading the world in new ideas and methods (and dare I say it...technology) to organize labor.
I'm coming into it more from the other side, unionization as a way buffer against (and maybe negotiate something other than) sudden mass layoffs.
If I join a company and day one I’m the top performer I’d want to negotiate a better package for myself and I don’t want other people meddling in my negotiation unless I explicitly hire them to
I would say though this only benefits part of the society and comes with huge drawbacks too.
See also, the surge in recent tech layoffs (which he cites in the article).