I know absolver technically isn't bad. I built 2 pieces in one game 2 years ago against a shielded base together with artillery and it was kinda efficient.
Absolver is too specific of a tool to be used in many games. It can crush shields, but it's projectile can't really reach specific moving targets like commanders or harbs. It's good only for bubble shields. Also it's t3, so most games won't get to the point where you'd build it. This is fine, but it's a shame to see such an interesting unit is so rarely.
People often complain about firebeetles being gone, but rarely about absolver bcuz it was never really a thing.
Absolver isn't bad but it's super niche.
The(partial) solution:
make it t2, so that it could be used earlier- at tech when shields kick in and players could actually get more opportunities to use it throughout the game. Obv it would require to adj it's stats to be a bit more in line with t2, while kinda staying relevant later(like medusa or obsidian), or maybe just making t2 absolver from scratch just the way it was done to the antiair at t3(although I suppose adding units is a nono)