In the fight between Athlete's and Team Owner's 'it doesn't matter' to any of us. It's a zero-sum game, they're rich people arguing over surpluses.

For commodity workers in industry, without unions it's possible they are mistreated, in which case, it's better for everyone if there were to be unions (although I think some kind of agreement would be better than unions). But workers unions can also leverage considerably more power than is better for everyone and make the company and industry struggle.

Unions are a form of power, they work differently in different scenarios, and the scale and relative power matters a lot.

It's just not sufficient to say 'there's a union over there therefore we should have one' or 'unions are all evil' or 'unions are always better than not' etc..