There are two routes to go when it comes to gun safes. Either go cheap with basically a steel box or spend $7000+ for actual fire safety. Everything in the middle is a waste of money.
A basic steel box will keep the kids and mentally unstable people safe. If you want to upgrade a bit change the original lock for something better. Find a tight space to wedge the safe in and bolt the heck out of it. I squeezed mine into a tight nook and added more anchoring points. The idea is that the placement doesn’t leave much room to get leverage on the safe. Then again, a grinder with a cutting wheel can make short work of it.
Most “fireproof” safes don’t provide much protection in the real world. When I was a firefighter I never saw one actually save the guns. Many also provide even less security than a basic steel box. Some of them are built with such thin metal they can be cut with a regular skill saw. Fireproofing is often just sheet rock. That’s why they are so heavy. It’s because of drywall, not steel.
A cheap way to upgrade a cheap steel safe is with electronic sensors. A buddy of mine has a sensor package that monitors heat, humidity, and motion. When tripped it sends an alert to his phone. One time it went off when there was a 3.0 earthquake so they do work.
Probably my best gun safe security is that it is pretty well hidden. If you can’t find it, you can’t rob it.