They are different games created by different people with different goals. It not only adds to the argument, but it is the argument. Not real complicated.
What you miss here is that is how POE works. Diablo has never worked that way. Has absolutely ZERO to do with “how the genre” works.
Items from seasons rarely came to eternal in D3. You are again basing your opinion on POE. I don’t want either game to do things like the other. I am definitely not alone.