To be fair, the engine room would be the first place to blow up in a catastrophe.
Consider his mentor:
And, assuming that Scotty survives longer than the events of Star Trek Generations, after being rescued from that transporter, he’ll have lived longer than any of them. Pretty sure he hasn’t had an in universe death yet which has been stated, but he was still kicking in 2369.
I believe Beta Canon puts him as the head of Starfleet’s ship yards. Sure, he originally wanted to retire, but I’ll bet it’s a real cushy assignment. And he gets to scratch his engineering itch whenever he wants to get his hands dirty.
Engineer 1: “Everyone look busy!”
Engineer 2: “Why? What happened?”
Engineer 1: “Scotty came down personally to inspect the new reactor designs!”
Engineer 2: “Oh shit!”
100+ year-old Scotty: “WAS THIS FLUX REGULATOR PUT TOGETHER BY A BUNCH OF MONKEYS?!”