Solo difficulty needlessly harder as you progress in end game? (Spoiler free)

Is it me or does the game seem to just throw more enemies at you higher you get in the season content.

There was a massive jump for me from finishing the game story solo to being dumped in the current season.

So much so that it has been frustrating at some points. Like Special Shielded enemies that I have never been explained how to brake their shields not that mechanics work all the time.

This isn't just a complain... This game just feels like RedFall but with a DC Skin... Much like redfall the story was neat, but the game play has been... Less than stellar. Forcing you to use several needless combo attacks because the develops made it, so they want you to do it... like Radfall at lest you have several ways to, "Skin," a cat as it were.

Heck Even the game play loop in Avengers feels better than this... You have real progression... Lets not even talk about the gear upgrades... I have seen gear I got at later levels that is a higher Quality have worst over all stats like WTF...

Things I know and am working on... I have been leveling up all other characters so the bots are, "Better." However it is a slog, and to be honest I have tried Multiplayer, and people I have experienced so far are not the kind of people I would like to play with. So I want to play by myself personally Since no one in my IRL friend group seem interested in the game.

So my question is why are they punishing solo players with a needlessly harder mode than if you had 4 real other players?