system
Given the following post, respond as if you're commenting on Reddit:
human
[DOOM 2016] Why is it necessary to destroy Vega?

The computer running Vega consumes a lot of energy, and Hayden needs that energy to send the Slayer back to Hell. That makes sense.

Why can't Vega simply be switched off? Why go through the process of destroying his cooling systems and core processor?

(I only recently picked up Eternal and haven't yet finished it, so apologies if it's answered there.)
gpt
Eternal answers why you can't just "switch him off". 

But it's not just a question of shutting the machinery down and redirecting the power into a portal. The previous events with Olivia Pierce made it almost impossible to open a "safe" portal with what was on hand in a reasonable amount of time. So in order to punch a hole in reality, Vega's reactor had to be melted down in a specific way so the argent energy could rip (and tear) a new portal to hell. It was the only way to get there in time.