Do teams still need front-lines?

No. No frontlines = nothing for the carry to have in front of them to soak cc and damage

Depends. Some carries have such ridiculous selfpeels that with the help of enchanting supports, they barely even need a frontline. But it's better to have one I guess.

I think there was a four tank/support + carry LCS comp just last week. Almost every game is 3 tanks/support and a utility pick + carry. Rarely do you get the occasional second squishy damage pick (Kha'Zix/GP normally).

i hope cuz adc and tank meta are boring af we need asassins baby