I think the biggest problem is that the Marvel cinematic universe seems to have better acting, better writing, superior interconnectedness overall and stakes that are well calibrated to its cast of heroes. In contrast, I find most of the characters' hyperfocus on specific neighborhoods in Marvel's Netflix shows to be frankly ridiculous and annoying. I also find myself wishing the main characters would just kill the villains a few episodes into each series. It boggles my mind how much waffling and angst goes on.
As a followup to your last comment though, my point had nothing to do with HBO becoming Netflix. I don't even think HBO should try to become Netflix at all. I would prefer for HBO to remain the curated content space that it is, precisely because I'm concerned with the quality of content. Strictly speaking, the ratio of quality content to junk on HBO is far, far higher than Netflix's. It's not really about HBO or Netflix being more successful in becoming the other, it's about quality. Regardless of whether or not HBO is close to becoming Netflix, Netflix is so far from becoming HBO I don't even think they could recognize an interstate map outlining the route.