The problem I have with MP is that it is extremely dull. There's nothing really going, feels like an alpha or beta. UI/UX is atrocious (don't even bother trying to use the in-game menus to join a party, join friends via Steam). Lots of stuff partially implemented and/or not explained (difficulty levels for missions and abilities levels for planes). Abilities and parts are very abstract in what they provide (at least it has been
datamined).
Meta is unbalanced hard in favor of LAAMs right now. Warfare is an auto-win for the team that did remember to bring an EW aircraft (bonus points if it's a Barricader).
Leveling and uncapping planes is fucking boring, the already boring progression is artificially slowed down by the golden blueprints requirements, while silver blueprints might as well not exist in their current form since you're just gonna buy them from the store.
There's not enough content to keep you interested in playing (even just interesting liveries to unlock, weird there's so few when 7 turned into a nice liveries library with the updates over the years while the ones that you can unlock in MP are so uninspired) and gating new planes that can also be used in SP behind a limited pass is also extremely gay.
And this is only the gameplay side. It manages to be boring even on the setting: as far as I'm aware MP takes place in an alternative world/universe to justify why we're fighting over locations and against superweapons of the previous games. You're a mercenary pilot for a random corporation enlisted by an ??unspecified?? client going up against an ??unspecified?? enemy.
They could've easily tied it in with Strangereal by making you a pilot for General Resource, with the sorties you fly framed as being part of the narrative leading to AC3 (
IF Simon's simulation about the Corporate War is actually accurate anyway). You could then simply justify superweapons fights as being simulations to gather some sort of data if you really wanted to.
But I can also see that it would've required a much more hands-on approach by Project Aces (if the narrative that Online is being handled by a different team is true).