Reincarnated as villain/villainess trope thoughts

Now, I don't read this genre often/at all, but I want to express an opinion I have of it, and hoping those who have read more of this genre could weigh in why this opinion may not have the full picture. But my opinion is, I get really upset/sad when the original villain/villainess is just said or made out to be irredeemable, destined to just be immoral/bad and have their terrible end. I just feel like I don't care how impossible it is because of what they've done or how immoral it is to try and redeem them or have them be 'normal' after everything they've done, I just want them to have the same kind of journey/story the MCs got when those MCs reincarnated into their bodies. I don't like how the MC's get to have growth, love, a different treatment, whatever it is they get when they are reincarnated into these character's bodies, whiles those original characters themselves are just deemed or said to not be able to have that, they're just gone, just the original, just an 'outdated' version, here comes an 'improved, better version' with the MCs. I just don't like it :(

This though, is where I wonder if I don't have the full picture because of not reading a lot in this genre/trope. The only thing I've read that had this trope was SVSSS and even then I haven't read the novel, just watched the donghua and consumed some fan content. But I just felt so upset when the author said Shen Jiu, the OG Shen Jiu just wouldn't change. Like that's fine but I still want them to have a little in essence of what the MC got when he reincarnated into Shen Jiu's body, idk how that's suppose to look like I just want it And this then doesn't make sense bc I don't know what I want is supposed to look like! ╥﹏╥