I wish I was as optimistic as you. GPDR was already supposed to be such an improvement. I have no doubt that current Apple's dance won't work. But I don't think any European company will actually benefit from DMA. (I'd say the ones who will really benefit from it are Epic Games and Google, maybe Mozilla a bit)
That being said, I'm very happy the EU implemented the DMA.
It is funny to see American companies scream "that's not fair" when faced with a functional government.
A trade war is the last thing the EU wants, especially when they are completely and utterly dependent on the US for technology and protection, so it's very unlikely that the EU will get all extreme on Apple or other US tech companies.
It will push as hard it can but we will not see a protracted ban. The EU understands that it can only push so hard before it starts a trade war and harms itself out of spite.
Oh I think the EU can rule whatever they want on their domestic market. Apple can try to find all the holes they want, the Commission is probably just taking notes of those holes to fix them in the DMA 1.1
I really think Apple (and Meta, fwiw) is making a huge mistake if they think they are in position to negociate anything. DMA is here to fix competition issues on the european market and if the goal isnt reached, there will be enough iterations until achievement.
It's not a fight again Apple, it's about preserving the core of what is the EU : the European Single Market. The European Single Market was created after WWII with the goal to enforce peace on the european continent. The Single Market IS the European Union. There is no way they'll let Apple get around this. The only thing Apple don't understand is that the EU is traditionally really slow to act so they had an entire decade (and more) to think that locking access to the market in the EU was fine.