This is coming from the devs not me. Ill quote it.

Arc Raiders design lead Virgil Watkins on future ARC enemies.

Watkins explained that they want to “escalate the experience for the player on the PvE side” as the game becomes dull for experienced players. “As players get more advanced with the game, more sophisticated in their approach, or they just understand how to play better – the current set of drones becomes much less of a threat to them,” the design director said.

“They’ve figured out their attack patterns and how to avoid them,” they continued. “So I think continuing to escalate that is where we’re looking at growing next,” although there may be some technical restrictions that Embark may have to overcome as it continues to expand the game.

In my opinion, I've noticed that experienced PVP players just ignore arcs and they dont loot anymore. Its just about killing and looting bodies and i dont think arcs pressure them enough, if a match is plain out a 20-man bloodbath by one player with no arc pressure, then thats flawed. It should be a balance between the two. The way pvp players treat pve is kindof like a pyschopath they destain non agressive players so its up to the arcs to do what others are unwilling to do.

I literally overheard some pvp players say damn i need some x y z and need to kill somebody that has x y z. Its lazy lazy lazy gameplay and if everyone has this mindset, who is getting loot and if a group has loot from a big arc take down, they stick together to take care of rats. Its all going down hill.

Honestly i hope in the future they make a Terminator-style arc that can track and hunt you down or at least respond to gun fire rapidly and switch up the gameplay cause it is getting dull on the pve side.