There’s a mountain of web capabilities that Apple lead the charge and either invented the specs on, or adopted before others, on to make more native-like experiences for the web. I think things like backdrop-filter, position: sticky, and css snap points do a whole lot more to make websites feel like native app than stuff like WebMIDI.
I think there's plenty of 'malicious compliance' and pettiness in Apple's recent DMA stuff, but I do not think removing chromeless home screen bookmarks was one of them. I think they took a strict interpretation of the regulations and don't really care too much about them so just removed them.
I think Apple just has a different philosophy and priorities for their web platform, putting a higher value on privacy, performance, and efficiency than Chrome.