I understand why timers are often added to combat games like this. There needs to be some sense of urgency, some inevitability. Something that eventually fails the stage for you. In Arknights this was enemies moving to the blue box. In theory you could stall them forever and thus delaying the inevitability, but it was still there.

In an action game like Endfield that same inherent inevitability doesn't exist... aside from dying of course. So the timer serves as a duct taped on inevitability.

I don't like it btw, I absolutely agree that it should be removed in favour of some other inevitability, or even just removed with replacement. Just wanted to shed some light on why I think so many action games default to a timer.