Mozilla is unhappy because the use of browser engines other than WebKit will be restricted to the EU, forcing them to develop two different apps.
For an independent browser like Firefox, managing two browsers is not easy, so it can be forgiven that this could be seen as almost harassment.
Also, the fact that the use of browser engines other than WebKit is limited to iOS means that the use of WebKit is still forced on iPadOS, which also increases the effort for Mozilla.
Oh yeah generally I’d agree, with firefox I just think it’d be better to do what will push the fewest people away as long as it’s possible to maintain development.
Sadly yeah, I was just like “screaming with anger” about what Apple does, and seems everyone just agrees and keep playing their game.