[nodamage]

Companies are free to set their own prices. Setting a price that matches your competitor's price is a standard business practice and is not considered price fixing as long as there was no coordination with the competitor.

In other words:

1. If Apple went and talked to Google and Microsoft and they all agreed to set the price to 30%, that would be price fixing.

2. If Apple looked at Microsoft and saw that they had set their price to 30% and decided they wanted to do that too, that is not price fixing.

[mekster]

Why would those 3 platforms consider lowering their fee if that isn't going to really increase their market share?

It's simply a monopoly situation that competition isn't even required to sustain their positions.