PvE is the same in every game mode. The challenge posed by players may be completely absent, through player choice.
PvE isn't the same in every mode, because the presence, or the threat of the presence, of other CMDRs can significantly change the experience, even if there is not direct confrontation between CMDRs, and even direct confrontation between CMDRs does not preclude conflict with the rest of the environment.
I do not trust players to "play" their roles properly.
Ultimately they shouldn't have any choice, but to behave rationally.
Unfortunately, the rules of the system...not just the rules players operate under, but the rules that define the in-game setting...are not remotely up to the task of depicting the setting most of us would expect, or that Frontier wishes to show. Even NPCs can't do their roles justice.
Almost all RPGs are like that, Deus Ex, The Witcher, Skyrim. Also many strategy games like Total War or the Paradox games. FPS games usually neither get harder nor easier, they just remain shallow.
I really don't like the difficulty scaling mechanisms in most video games that have them.
The only sort of difficulty scaling I find broadly acceptable is based around rational actions and reactions, fame vs. anonymity. Inflationary scaling is something to be avoided...unfortunately, it's by far the simplest, and thus the most common.
Even many of the single player titles I really enjoy are crippled by this. Take
Homeworld...on my very first play through I had to start over because I did too well in one mission, and was presented with a virtually insurmountable obstacle in the next. It was much easier the second time around when I deliberately chose sub-optimal courses of actions. It felt like I was being punished for learning the lessons the game was teaching me, as well as for applying intuitive, real-world, logic. For example, there was no mention of there being any FTL communications in Homeworld, so I logically assumed that if I captured or destroyed
every enemy vessel before any of them could flee, my opponents would be unaware of my progress. Turns out it didn't work this way; and on the next map, they apparently knew to bring three hundred ships (and apparently had three hundred ships in reserve, just waiting somewhere, rather than putting them to use).
Most Bethesda games are even worse. By default, almost everything levels up with you, which totally destroys any feeling of credible demographics as well as introduces absurdities like 20th-level wolves with enough health to ignore any environmental hazard, or bandits wearing so much daedric armor that they could retire and buy their own kingdom somewhere, rather than try to steal my character's loaves of bread. If I can even be bothered to play a Bethsoft title, I mod the snot out of it to completely remove difficulty scaling (and often tone down the player-character's own inflation)
When it comes right down to it, I dislike most level based
and most loot based games. If it's an abstract title, I expect to see character skills improve, but I don't like seeing character stats just inflated to the point they can totally ignore hazards that would affect more mundane people. If it's a less abstract title, I expect my own personal abilities as a player to be the overriding factor...once basic tools are acquired.
I actually liked the combat in the
Thief games. It was expected that combat would be avoided and your character never improved in combat ability, so when I was able to take out a half-dozen guards, who were each statistically superior to Garrett, simultaneously, it felt like a real accomplishment.
Crysis, though far more combat oriented, was enjoyable for similar reasons...and for the stove challenge (where you see how far you can get only killing people by throwing a kitchen range at them).
Anyway, I don't feel difficulty scaling, the way it's implemented, in any of the games you list, does anything but harm my enjoyment of them.