Umm, yes it is. There are plenty of government regulations of companies that are like this but you're so used to it elsewhere that you don't notice or think about it.
If Apples decisions were truly so anti-consumer, then consumers would use a different platform, such as android. This is as a developer who has to pay the App Store fees.
All this regulation has done is make the app acquisition experience on iOS worse as a whole and laid a minefield of vague legal regulations and lawsuits yet to come.
You could argue this specific regulation itself is bad -- like you can with all other regulations -- but the concept of regulating a business for the benefit of consumers has long been already decided everywhere in the world.
At the minimum, this was a poorly planned and executed regulation as displayed by Apple here.
TL;DR: this is nowhere near the most-reaching one, nor the first to regulate how businesses can sell stuff in their own markets.
Apple and Google (and Facebook, and Amazon, and Adobe, and and and...) are not special: they are just entitled.
What? That's a large part of most government's responsibility. If we used the logic you described above, then the US government should never of touched Big Tobacco, Bell, Standard Oil, US Steel, ect.
I don't really want to debate if the multi-trillion dollar conglomerate known as Apple is a monopoly, however I'll happily engage with anyone who thinks a government shouldn't regulate a company they concluded to be anti-competitive and monopolistic.
I have an example from Germany, though, for you: stores selling newspapers and magazines basically have no choice on what exactly to sell. The goal of this regulation is that no matter where you are, basically all publications are available everywhere easily.
In that sense stores are sort of forced to act sort of like ISPs for print publications. They just have to offer everything.