Try DaVinci Resolve

That doesn't answer the question. What make many video editors, regardless of their licence, so crash prone?

Image/photo editors never crash (or so rarely), same for most modern audio editors / DAWs and the later can use an awful lot of memory too.

Probably the state of video drivers.

Seconded, it is a seriously high quality product and free as in beer in the best way.

Only works on like RedHat? No other Linux

Centos is the only officially supported distro, but it works just as well on any other. In some cases, you may need to install some extra dependencies, but not much

Only officially supported on RedHat, perhaps. Works well on many other distros (I run it on NixOS).

I've successfully run it on KDE Neon (Ubuntu based)

Had no problems running it on kubuntu 22

It runs well on Arch.

Not saying that you aren't right.

But using Davinci Resolve in an old cpu (as in 2012 cpu) it is a complete pain.

That sounds like a RAM issue.

If you've got a faulty RAM chip, a memory-intensive use like video editing will reveal it. And it usually does so by crashing.