Usually, when there are spots like this, they really aren’t that large, and can be ran across in just a couple of seconds. The size of them needs to be increased, so that unless a player interacts with it an creates cover (either through sandbags, trenching, or smoke), running through is much more risky.
Additionally, there is a lot of it that just magically cannot be trenched currently. Usually if there is a crate, or some piece of pre-existing structure that even when destroyed you cannot dig there. Which is why leaving it as an open blank slate to be used by players to actually work with is a better option.
This benefits both defense and offense.
If you are thinking “how does this benefit offense”, consider that pre-existing structures lead to people knowing exactly where you are going to go every time. Leading to the same monotonous gameplay every time.
Whereas through my suggestion, you can create your own trench line, foxholes, etc and pop up where they may not be expecting it, or setting up a MG/Sniper position where they don’t automatically expect it.
In MY opinion, they CAN, if there is enough area that they can actually be useful (where you can dig decently).
Not EVERY player is likely to use them, but digging foxholes, popping down a medbox, and pushing forward to keep doing this process, (I use a medic squad for this purpose), makes for a lot more entertaining fights.
I’ve even had players thank me after the fact as it saved them a lot of lives, where they could get in cover to survive explosions, get more meds when wounded or knocked, and have more positions from which to launch attacks.
Its a lot better than: run at objective, shoot a couple times, die, respawn. It actually helps facilitate FIGHTS, not just exterminations.