Multiplayer shooters should get "pure" healers that can't shoot
One way to breathe a new life into multiplayer shooters could be removing any guns from healers.
Make them potent, but vulnerable!
Why is it important:
Players that don't like shooting, but love teamwork would finally be represented (yes, I'm speaking of your girlfriend!)
Having to protect healers would benefit more organized teams, rewarding teamwork
Healers would have a more dynamic gameplay revolving around avoiding damage: stealthy movement, ability to quickly traverse dangerous zones, coordination with fellow teammates are all required to benefit your team as a healer
What might need to be tweaked:
Healers should be made into the only revivors, and we should either punish death more (which we'd better be careful of if that's a dynamic game) or give buffs on revival
Healers should get more movement abilities to increase survivability. They may also get speed boost when running towards teammates (similar to Conduit Savior's Speed in Apex Legends)
Team compositions should accommodate for several healers as to not introduce a single point of failure
Overall, I think it could introduce a new dynamic to team arenas and skirmishes, as winning now requires more coordination within a team and better understanding of everyone's roles.
Medic in TF2 is a pure healer. The only time their weapons come out is if they get separated or get surprised by a spy. In high-level play, basically never.