First, contrary to the headline, this was *not* a ruling by the National Labor Relations Board. It was a ruling by a regional director. It can and will be appealed to the full Board. The full Board ruled against college athletes in a similar case in 2015, but quite likely (but not certainly), the Board will uphold the director. Still, we have to keep in mind that this decision is not final.
Second, there is an advantage to unionization: it makes it possible to negotiate a salary cap and a cap on NIL. The NFL's salary cap is legal only because it is part of a collective bargaining agreement with the players' union. Steps that would otherwise be a violation of anti-trust laws can be OK if they are part of a collective bargaining agreement.