Fan service is cool, but it's beginning to become a bit too abundant in the absence of good storytelling. I'll be honest NWH suffered from this. NWH's ACTUAL story is really a mess. I think people overlooked that because of nostalgia.
I expected Scarlett Witch to be controlled by something darker. Be it Nightmare, Dormammu or Mordo. I thought the illuminati to be more impactful in the broader story. Mordo is just there. They don't seem to know what to do with him or understand he should be a much bigger part of the arc.
There's a lot of 1 and done so far in Phase 4. Setting broader arcs was so much better in the earlier phases. If Kang is the new Thanos, tease him more like they did Thanos. Maybe have the Illuminati know of him, something. This was my same issue with the Eternals, so easy to at least "talk" about something adjacent that expands the story like the earlier phases.