That’s the literal definition of anti-competitiveness.
No it isn’t. That’s actually a very common store policy that’s been in place since the days of brick and mortar locations. Why do you think you never see any platform listing games at higher or lower full retail prices than every other one regularly, even when they’re not on Steam?
Where did you get the idea that this was the definition of anti-competitive? There are so many more things that define it more, like buying up all the competition or taking a big hit on loss leading pricing to force the competition to undercut themselves and collapse.