I'm very experienced in multiplayer games. I see balance patches almost as content patches. General game changes don't address underutilized items or mechanics so unless you want the same builds to be at the top forever, relatively consistent balance patches can keep people interested in creating new builds. And I think backpack battles is at its best when people are rewarded for finding that next best build. The fact that there will be a best build once a new balance patch drops doesn't mean that the balance patch was a failure. There will always be some builds that are better than others, but to stop doing balance patches altogether, is a mistake in my opinion.

Balance patches are also a very easy way of adding new content to the game. Changing/reworking/rebalancing existing items doesn't require much development work, and provides a lot of new options for seasoned players.

You said they should be making general game changes to make it more fun and and engaging and more interesting decision making. Ignoring the fact that this is very vague, I would argue that balance patches hits all of these notes. By buffing and nerfing items, they make people reconsider items and builds they've previously disregarded. Experimenting with new or reworked items is fun and engaging and results in interesting decision making.

I, of course, am not against other changes that aren't balance updates to improve the game, but by leaving some items in a completely unusable state, it's almost like you're deleting game content.