I agree with your point. However, you seem to ignore why it even became an issue in the fist place.
In 2013, XB1 was both weaker AND $100 more than the PS4 so it's not surprising that people talked about performance. People also talked about 360 outperforming the more expensive PS3. Microsoft claiming that cloud computing would make XB1 close the gap only drew more attention to the matter.
In 2017, XB1X was stronger but it also cost $100 more than the PS4 Pro so this was more in line with expectations. From 2017 till today, XB1X has been widely described as the best place to play multiplats (just like 360) so it's not entirely accurate that "multiplats only matter when PS has the upper hand".
In 2020, Microsoft claimed that Xbox Series X is the most powerful console ever built with Phil Spencer adding that "games will look and play best on Xbox Series X". I understand why it's frustrating for an Xbox user to see the recent comparisons but I don't understand how it can be surprising at all that the issue gets a lot of attention when games end up looking and playing nearly identical on the 2 consoles.
OT: Both consoles will be fine and the differences between multiplats will be negligible down the line.
Imo PS fans struck the first blow when bragging about teh CELL. From that moment on Xbox and PS fans fought over the power narrative. Hence Xbox fans bragged about 360 being easier to develop for as the first counter to the narrative. And so on and so forth. The pendulum was temporarily swung back in their court as of now and you bet they aren’t gonna waste it. Ultimately it’s console war zealot psyc 101 and there’s not enough time to describe it lol.