It really doesn't matter if it owns 25% or 90% of the OS space. Anti-competitive practices are business or government practices that prevent or reduce competition in a market. That is exactly what Apple is doing.
Of course it matters. Buy an Android or Microsoft phone; leave iOS behind. There's plenty of choice. If you don't like Apple's practices, buy from the competition. If you don't like Microsoft's monopoly, you'll find that it's a lot harder to ignore them. Many software companies only have Windows version because that's 90% of the market.
