1. Decrease enemy agro range, when I go to a mission and enemies in a nearby mission also agro over if I get to close is absurd an d not good programming or world building.
2. Increase power levels of quest/missions rewards I'm near the end now dark matter guys are power level 1500+ through doing missions (all up to now) I'm level 48 and power level 1389 I'm getting annihilated if bulwark robots or 20+ guys come leading onto point 3
3. Higher difficulty mobs should do less damage and have less hp than they do, I just did a mission where I had to fight 20+ guys and 2 bulwark robots while protecting an objective it took me 2hrs no one else came to help I had to take out 1 or 2 mobs run refill hp/ammo rinse and repeat, the bulwarks took all my ammo just to knock off shields thank God I had damage over time grenades because if you let up damage for more than 2 seconds they regen that shield back fully in 2 seconds.
This does go for earlier hard mobs too like the rocket launcher guys you can only hurt from behind its stupidly hard to solo them.
4. Decrease mob amounts in some places I came around a corner and due to the agro range thing a lot of mobs know your there before you know where they are some times. Anyway 4 rocket launcher guys 4 shotgun midget shields guys and 10 or 12 machine gunners this goes for any faction of enemies a mix of 20+ mobs like this coupled with the agro ranges can be ready to kill you before you even know it, it doesn't need to be this much, that amount is overkill.

These improvements will keep me playing, I've talked to many people these 4 factors seem to be a common agrevience in the general chat, I know some will say get a group etc but you claimed all normal content would be soloable, so far it isn't unless you take advantage of bugs or places enemies can't get to.
Finally I've never got games where enemies 'scale' with you what's the point in leveling up then why have levels if you can't go back to earlier areas and squash easier guys. In that I'm very old school and loved out leveling areas in RPGs and MMOs.
Please consider these 4 pointers
EDIT: PS4 player if that helps

As an additional item the mobs near the end are now 2000pl I'm somewhere at 1436, it's a absurd