I was thinking the same thing. You could unlock the cards based on level. So you don’t just get level 11 cards from the start.
If memory serves, there is already a lv requirement for the higher lv cards (can’t use em if you aren’t within x lvs i think).
It also encourages actually doing the achievements because you know for sure they won’t “get wasted” (completely) because they will carry over to what ever new character you make.
You’re correct that they have level requirements, they are really low though, that’s why they should be given at higher levels to prevent Team Level spam.
I really agree on the achievements, it would be nice for titles as well. I want to be a Shady Geologist on my future alts.