I am of the opinion that maybe this is exactly the reason (in addition to the other mentioned things) that Satoshi used "we" in the whitepaper, because it is known that he drew his ideas precisely from the works of some other people who, in some way, long before him had ideas about to what he finally implemented.
In addition, considering that Satoshi was a man who was aware that he could not do it alone, I believe that in this way he wanted to repay those with whom he cooperated after Bitcoin came to life. Therefore, he never wanted that project to be something that would be associated exclusively with one name, he knew that Bitcoin would never succeed and be what it is today.