I fought in Ukraine and here's why FPV drones kind of suck

I think you need to compare it to other man portable guided weapons like the FGM-148 Javelin. The Javelin is much much better in all respects, except perhaps range. But is about 100 - 200 times more expensive.

If you can afford* the Javelins and the TOW's of the world that's what you are going to use otherwise, you are stuck with FPVs.

Afford means not only fiscally, but production capacity wise as well.

Doesn't a single javelin missile cost almost 200k? The drones I've seen I'd budget at 150-300$ plus explosives. I think that puts the javelin more at 500-1000x as expensive imo.

You need 15 drones to do what a javelin can do though, and that is at best. If the tank armor is good a small drone cannot do any damage (that is why drones try to fly in open hatches - bypass the armor), while a javelin can go through modern armor.

Tank armor can be good as it gets, the problem is you can't have good armor everywhere on the tank otherwise it would weight hundreds of tons. So a small drone doesn't need to penetrate tank where it's best protected but to disable it (hit APU, tracks, engine...).

Obvious solution, make the tank amour a drone crawling around and building up in direction of danger?

The obvious solution, is duct tape a bunch of corrugated steel around the tank, https://en.wikipedia.org/wiki/Turtle_tank