That’s a bold claim. It’s not all black and white.
If you’re talking about REAL competitiveness, we’re talking about a money prize or at least full control by the player, right? It doesn’t work that way in real life either, why should it be that way in digital?
The well known board game backgammon has tournaments with a money prize pool (I’m surprised in 2020 they held it somewhere) but it doesn’t change the fact that everything relies on a dice roll and people played this game for fun along the centuries. Bridge and poker have tournaments, but it all relies on cards, your memory and your chance; there are things that you can not control but fans accepted it.
Do those examples change the fact that people enjoy these games for fun? People enjoy board games like chess, which is very competitive by nature, card games around friends or even try PvP in DnD, which is closest thing to an ARPG as a board game.
You may be angry at your uncle for beating you at backgammon or poker in a very hot summer night, that’s not competitiveness. If you get beaten in a video game while playing a public casual match, that’s not competitiveness either. There tons of other non-comp board, card and video games out there, it’s a facet of the thing and randomization will be a big portion of these for the lackluster UI or control.
Only real fans accepted them as competitive games while rest of the world enjoys it as much as those fans who play competitively without the feeling of rivalry.
For Diablo 4 same thing gonna apply. Some fans will accept D4 PvP as it is to make it challenging. They’ll become passionate and will look for a work around for its shortcomings even. When that doesn’t work they’ll give feedback to the developers. That doesn’t change how other people treat PvP’ers. If game gets a comp scene, that be just extra even if it doesn’t seem fitting.