What if the PS5 is the base platform for development because of their higher installed base? By default every PS5 version of 3rd party games will run well seeing how that was the system it was developed for with Xbox platforms getting a port.
Not necessarily. It's not like developers would cap the Xbox version. In fact, with DRS, more room for framerates (up to 60, instead of just 30), and ray-tracing, XSX would have more opportunities to show its power difference -- if there were a big power difference b/w the two consoles.
This was true last generation as well. Several developers sung the praises of development on the PS5 before it even came out. The power of the Xbox would be meaningless and would hardly be something to celebrate if the PS5 and XSX had parity. There was never a massive delta between current generation consoles and using this title to declare a PlayStation engineering victory is a little strange.
Not true. With PS4/Xbox One, PS4 had the power advantage because it was more powerful, and it showed. Then came Pro and One X. Despite games being primarily developed for PS4/Pro, One X consistently showed its power advantage, because it was indeed more powerful.
If games being developed for PS hampered the Xbox version, how come One X showed its power advantage so consistently?
The reason that we don't see differences b/w PS5 and XSX isn't because games are primarily developed for PS. It's because these two consoles are extremely similar and there is no noticeable power difference, as we have seen in over dozens of game comparison videos by now.