there's a difference between balancing for low level players and listening to bad players who whine on the forums. Making units easier to use or less punishing helps new players more easily get into the game and doesn't take listening to every noob who just started playing the game.
OH GOD, finally a decent post.
You balance taking into account how a unit is meant to be working and proper use of tactis/strategy (use of cover, abilities, flanks, positioning, etc).
ALSO, you can make QOL changes or makes things easier to use or remove some micro taxes on certain units. Things that the average joe will appreciate.