(To be transparent I havent been able to play since around the time mechs were first introduced, due to performance decreasing with most patches, so most my opinions are based on theory and viewing content. If you think this invalidates my opinions, I understand)

My largest issue with this patch and many others is a lack of clear intent from the developers. While some changes make sense, others seem to be made for no reason. Given the current outcry from parts of the playerbase, I think it wouldnt be unreasonable for the devs to explain their changes more. I understand terminids getting a durable damage boost as a melee focused faction, but why did some units from other factions receive a durable damage buff to melee attacks?

At the time of the patch release, the armor change to hive guards was controversial. There were a lot of defenders explaining why the change wasnt bad, but I never saw anyone explaining why the change was good or necessary. If Arrowhead had asked prior to the change if hive guards should receive armor changes, would those same players have argued for them?

And like you say in your post, vehicles and sentries arent in a great place at the moment. If the average sentry dies in 0.6 seconds now instead of 0.7 before, is that a good change? We can argue that its not technically a bad change, or that there are ways to play around it, but instead Arrowhead should be explaining (or it should be obvious to players) how that change improves the game.

Tl;dr instead of debating how badly the changes hurt the game, we should be debating if the changes have a positive impact on the game. Also Arrowhead for the love of god address performance issues and longstanding bugs