You seem to be unable to enjoy a good plot, with every death the plot just thickens more and more. On the beginning it’s easy to take the world as a typical isekai with demonlords incading the human realm but the more ypu read the more you will realise that there is something more to the world than what we see and read. So if the only thing you can read is that he is only dying without getting stronger then i guess you didn’t even make it past chapter 1 because he actually gets stronger with every chapter but so does the enemies he meet along the road. From dying to lowest scums to meeting the higher ups of the organisation controlling an entire empire