People tend to forget that people play games to have fun.
Constantly losing to what looks an unfair battle takes away that fun and the frustration level increases.
I am in the same boat. I HATE raids. In my view there is nothing fair in it.
I play with the best heroes that I have (the ones that the game gave me), I pick the best adversary that I can (based on what the game chooses for me) and I play with the board that the game gives me
These days out of 6 games wining two is a good round, and getting 10-15 kills is an excellent score.
It doesnt matter what I do, choose different adversaries, try to adapt my team, the end result is always the same.
The game has a biased interest for us to lose. Because if we lose we have the temptation to spend money to try to get that better hero.
For me it does the opposite. It frustrates me, in some games after 4 or 5 turns I know the game is already lost, its that predictable, and I refuse to spend money that deliberately frustrates me by making me lose unfairly.
The raid system should be totally in favour of a live player. You want to keep it happy imo.
And currently its not and its getting worse.