For starters, it is impossible to actually balance a game like this for multiplayer (without killing the identity of each unit / faction, anyway); there are too many variables. Something will always come out as the best way to win, and this will be 'the meta', and if you try to fix this because of outcry over 'the meta' you'll just create a new best way to win and a new meta. There's no end to it.
The changes are also always reactionary and based on incredibly spurious data. Most players don't actually test the meta; they just blindly buy-in. Older strategy games demonstrate the folly of this - new metas would crop-up on a regular basis in Brood War even though the game wasn't regularly patched for balance. People were just wrong about what was good or bad and someone would prove it every now and then through innovative gameplay (see: Protoss suddenly having favorable match-ups against Zerg when amateur players were shown by a good player how to use DTs and Corsairs).
Even if the task wasn't impossible, the multiplayer community largely has no competency at determining what is good or bad in the game and therefore they shouldn't be listened to.
On top of that, the multiplayer space isn't neutral. Players have a 'main' that they play with and they want their main to be the most competitive, so they advocate for 'balance' changes that favor their main. This is why just about every single balance debate devolves into fake test results, context-free complaints about how overloaded or underloaded a given unit is and, of course, talk about how the meta proves that [X] or [Y] unit needs to be changed. No overarching design philosophy, no interesting take on what the changes would mean for the narrative flavor of the unit - just calls for nerfs with spreadsheet pseudo-evidence.
The MP community is microscopic compared to the single player community, they cannot actually be satisfied because achieving balance will never happen, they don't want the game to be balanced (they just want their main race to be the best) and the changes implemented due to MP complaints are slowly making the game ever more boring. Units have anything interesting either removed or made so insignificant that it may as well not exist, because the moment a unit becomes interesting it is targeted for complaints.
I don't want the game to reach the point where every single monster is the same, every single line infantry unit is the same, every single archer is the same, etc, because a handful of players won't stop complaining about the stuff that makes units distinct.