Who's job is it to help the backline?

As a strategist main, I am a priority target for dives and other target pickers.

I have gotten very used to 2 or 3 enemies sprinting past or jumping past the tanks to jump me and the other strat, only for 4 people to turn, look at them then continue on their merry way.

I have gotten pretty good at surviving this and fairly regularly me and the other stray can keep each other healed up, only to see/hear: "NO HEALS!?!?!??!?!?!11ONE" or "HEALER DIFF"/"USELESS HEALSSSSSSS" from the chaps who sauntered off and left us to the venom/Spidey/star lord.

Like bruh?

When this has been pointed out in most of my games the finger pointing starts:

"ITS THE DPS THAT SHOULD HELP!" "NO ITS THE TANK" "HEALERS NEED TO GITGUD!!!!!"

My question is simply this:

Who should be helping the backline? Tank or DPS.

My underyhas always been, if you have two tanks, one should peel for the healers and if you're running a solo tank, the DPS need to help.

Or am I just apparently dumb and strategists should be killing dive, while keeping the team alive, doing the DPS of 3 duelists and probably tanking as well just to top it off, because that seems to be what the average DPS player and some Tanks seem to feel.

I should be clear, I play in or near the team as much as possible.