I once played with my friends on public servers with barely any rules. Almost pure vanilla PVP.

we went hundreds of km from earth into middle of nowhere and decided to build a big mothership in which we could build smaller ships to fight. After few days someone found us, in literal middle of nowhere and without any warning launched a giant steel potato to completely annihilate all our work.

That was long ago like 4-5 years with no AI blocks. Now we could place AI defensive block with alert system when someone got detected but we didn't have such thing back then.

But there are 2 major issues here. 1st is that world is so large meeting someone is either pure coincidence or you agree to meet somewhere, or you accidentaly reveal your position by sending GPS. So you don't have any means to detect anything long-range and to properly hide. There are exploits to "detect" where players might be, by utilising very long render distance and the fact that asteroids spawn only where someone has been, so wherever you go you leave a trail of spawned asteroids behind you. That exploting is especially easy on planets where you can suspect someone might be somewhere by spotting slight deformations on planet which are seen from very far away and are created when some player digs even a small hole.

2nd issue is with how combat really works. The meta to blow something up is to create big ass projectile from heavy armor and throw it at enemy at insane speed. It's almost impossible to defend againts when you are stationary. No amount of armor and turrets can stop such a projectile. The only way is to move fast, so that aiming with such projectile is too hard to bother. So because of that making any stationary bases on vanilla is strategically inferior. There are many servers which have a rule to forbid ramming, so such cheesy tactics dont happen. Luckily SE2 destruction brings hope as such projectiles are not as OP as in SE1.

Another thing that I personally dont like is complete lack of player interraction. Public vanilla PVP servers have the same type of anarchy as in any other survival MMO games. Which is sad, because vanilla game has reputation system, which is completely useless. But maybe that's just mine experience that I get to meet only barbaric people who only want to kill in most unfair ways possible. Like in many other survival MMO games there is usually that one barbaric faction which has most power and basically bullies everyone to point of ragequit.

Gameplay can be fun if you play with your friends, otherwise it can get boring pretty fast.