I hear you for that. My problem with the summons isn't even that they make the fight easier, it's that they completely change the dynamics of the fight and don't help you get better at the game. For instance, summoning the Mimic Tear turns the boss fight into a game of whack-a-mole for the boss. They get aggroed by whoever last hit them, so the fights simply boil down to hitting the boss, running, let your Mimic hit them while they're chasing you, and hit them again when they're running after your Mimic, and stay out of AoE attacks. It's not even that I have anything against summons, it's that they make the fights incredibly boring and devoid of any excitement, especially the beefy ones that can soak up 5x the damage the player can. Also as I said before, they don't do much to help you master the mechanics of the game, so in that sense, they become a "crutch".
Not a fan of how From implemented the Ashes at all in this game. Overtuned bosses for solo play, but trivial and tedious if you have anyone halfway competent with you.