I play almost exclusively multiplayer with pretty skilled players and war is completely imbalanced to the point of being anti-fun. In the CPL discord server almost every game that makes it to modern and completes an actual win condition is Military. The games that don't make it are almost always defined by war as well.
As an anecdote, I'm playing Hawaii Isabella (maya first age) in exploration going up against Ming (who was greece first age, Ibn Batutta). End of the age I have a city with 9 medieval walls, all filled with units in the districts and around them, all tier 3 units with 2 level 4+ commander providing Order and defensive bonuses and I have a +4 in war weariness against my opponent. Despite all this, he is 2 shotting my walls with his Ming Xunleichong getting bonuses from a variety of sources (no military endeavors in the game, so just city states, commander buffs, etc.)
He took a 9 medieval wall city entirely surrounded by my own tier 3 units without a single siege unit and only lost 1 or 2 in the process while I lost probably 15+ units.
Every multiplayer game I play against skilled opponents devolves into somebody winning via military, whoever somehow ends up stronger, and there's really not much more you can do about it. In the example I gave, the CS bonus he obtained is something that by definition I cannot and now I just lose the war.
Units in online speed are incredibly easy to spam as well, which makes the game drag on as all these players spam units to try and win a military victory since it's the only viable path for winning the game at the moment. Turtling and out simming your opponent to some other victory is actually impossible as a strategy against a competent opponent.
Please take a look at rebalancing/redesigning war deeply, with multiplayer in mind. Even the micro, which commanders were supposed to lower, is actually increased because of them. Having to micro units in and out constantly makes war exhausting and anti-fun