This is clearly the game you are talking about when you complain about fighting defenses.

Some notes:

You had 0 reclaim over the entire game, your opponent was approaching 20k.
You never intentionally repaired a unit.
You neither made a strider nor fac-switched for artillery.
You used no puppies for screening, instead relying on pyros which are frankly basically just as vulnerable.
You feared snipers enough that you didnt even try to screen to make firewalkers viable, despite the target rich environment of the enemy hoards.

Jacks need to be repaired to be a functional assault force, or they need to be overwhelming. Their standard use case is to attack, deal some damage or take out some defenses - Then retreat for repairs.

So, if I was to point out any one things its repairs. You need to repair the attrition you take attacking defenses, not just yolo once the shots start firing.