SSF casual player - t17 maps are really bad

I've killed all non-uber bosses kinda "fine". Sirus, Maven, Shaper, Elder, all gone without too much effort, so I can say my build is fine.

I don't think I'll be able to do the Uber bosses, yet, but I can't even finish a single t17 map.

First time I rolled a map like 10 times trying to get a non-rip mod, and made a mistake, because when I reach the boss room (after skipping some soul eater rares), it was possessed by 3 tormented spirits.

After a whole day I finally got another t17 maps. Again, rolled like 20 times and finally got a "kinda-ok" mod, but it had a Union of Souls mod. Well, this time I wasn't able to kill blue mobs, because they all get bigger and bigger as you kill them.

A single blue mod is stronger than the guardians, elderslayers or even Elder/Shaper. This doesn't make any sense.

So, what is the purpose of t17 maps? They are harder than the end-game bosses? This doesn't make any sense.

I can't imagine how SSFHC people are playing.