Guild Wars 2

I just wanted to know whether if the trait is good in PvE? Can monsters crit?

Yes, monsters can crit.

Fun fact, the thrown rocks by the enemies in Bloodstone Fen will only knock you down when they crit. If you have stone heart active and are in earth attunement, they can’t interrupt your gliding.

When I made my asura ele, I ran around a lot while 20-30+ levels below the nearby mobs. When you’re 10+ levels lower, mons always crit. Also their crit damage scales with the level difference. So I took stone heart and was able to facetank them when I would have otherwise been one-shotted.

Also there are some mobs that crit a lot in normal comditions.

Worth noting that legendary opponents (the ones with the purple picture border) cannot crit. So if a fight only has one of those and nothing champion rank or below, the trait won’t do anything.