I don’t live in an EU member state anymore (i’m from the UK)
Obviously they should drop the BS app rejections, Spotify (or whoever else) should be allowed to use their own payment processor, talk about promotional pricing and link out to their own site or any other site (assuming that does not compromise the privacy and security of the end user). This is an absolute minimum.
If the third party dev uses their own payment processor to facilitate an in app transaction Apple shouldn't get a cut of that. If I buy a kindle book in Amazons app I consider that transaction to be between me and Amazon. If I purchased a Kindle book in chrome on my Mac Apple would get nothing.
Apple should open their services up to real competition on their platform. So no locking down the NFC chip so nobody can compete with Apple Pay, No keeping Siri commands exclusive to Apple Music for years, No restriction on what browser engine can be used etc etc
if they did all that, I don't really care about sideloading or third party stores. I think most would be happy with that.
Also their 'core techology fees' and 'new business terms' are obviously devised to make any circumvention of the App Store and its associated fees and policies completely non viable and should be rejected out of hand.