@Keetonman
Indeed the generic plot for Isekai are always like that, but there are some series that going the other way.
The most savage one I can remember is Kuro no Maou. The MC in that series keep getting trashed, nothing good actually happening to him, Shit has gone south.
There are also Hero summon but betrayed by their allies for example Shield Hero and Nidome no Yuusha.
I personally don't like Nidome no Yuusha since its a avenger type of series, so the story kinda squeezed into revenge purpose only. Unlike Arifureta since the MC doesn't give a fuck on revenge.
And there are also effort base hero for example The Wrong Way to use Healing Magic. He is blessed(LOL) with a teacher that can train him to the OP road.
I choose some examples that are available on manga platform, try reading this if you are interested. There are tons of the Isekai series out there that are not serialized yet.
"'My life was shitty then I died. But then I woke up in a totally awesome fantasy world with crazy superpowers and whoa all these girls suddenly are in love with me.' Isekai is nothing but trash-tier self-fulfillment for awful Japanese-Otaku writers."
The reason why they need a shitty past life is to give the MC a driving force to aim for more better life in Isekai, thus aiming/obtain the usage of OP skills. The girls are not suddenly in love with the MC(unless he have some charm skill shit), the MC usually interact with the girls,help and probably interested her somewhere with his personality. The girls are just attracted to MC just like a normal human.. nothing special here, just a woman loves a man. I don't get it why are you rant on the Isekai genre, Isekai is a good boy please don't be mad at it. The story tends to happen that way, can't help it. And lastly I hope you can change your mind on Japanese Otaku, since bad writer will just be bad regarding any of his job or succeed.