If you do get too far ahead of them and by no means want to make a character to play with them, you can still help them providing the following:
- Funds for weapon and pet enhacing so they catch up quicker.
- Materials and recipes so they can face the content with ease, making it much faster.
- Tips and tricks to help them leveling in the best spots.
- Helping them get a hold of the grinding spots.
- Moral support over voice chat doing silly things around with them.
What you can’t do is go with an increased level character and faceroll all over the place with them while still gaining benefits.
This is what would happen if you could get them to share exp with you, them being level 40 and you level 100, for example:
A) You go to their level range maps and wreck everything apart making them gain levels without doing ■■■■, feeling like they are worthless.
B) They go to your level 100 map and hide in a corner so they don’t die, because they will die, while dealing no damage to the enemies and earning tons of exp from you massacring all around you, skipping all the content they would have enjoyed at their pace, still feeling worthless.
Then, about level synching, that would make a whole new lot of problems in the game, one of them being people coming back to low level maps instead of higher level content, making the place even more overcrowded.
If you want to play with them all at all times, then yes, you would still be doing that content over and over again with the same character anyway, that’s what means playing together with people that keep doing the same content you already did one after the other. Why do you care if it’s the same character or of it’s a different one.