Do you think that if cricket players formed a union (maybe they already did, I have no idea), they would be paid as much as NFL players?

Of course not. NFL players are paid so much because the league can afford to pay them and still stuff their bank accounts.

The same goes for TV/Movie writers - good, proven talent is in low supply and there are millions at stake, so it makes sense to pay well to get the best. The 5th box office hit on a given week usually makes a fraction of what the 1st and 2nd does, so it makes sense to optimize for hitting the 1st spot and you do that by getting the best talent and you get the best talent by paying them more than others.

We (programmers) don't need the unions to be paid well because there's still more demand for talent than supply of such talent.

If it ever happens that we need unions to be well paid, the unions won't help much because you can't pay high salaries if you don't have high revenues.

Also, given that software companies are generous with stock options, as part owners of the business, we should be very much against overpaying the employees, even if they are fellow developers.