You have better sources than the one you put that give you that in XSX RE 8 it loads in 4~5 seconds.
From there, I repeat, IS NOTHING LIKE WHAT HAPPENS with ER. Especially a situation where PS4 with HDD loads at the same time as XS with SSD (and 3x faster than XBO) and that on PC any sata SSD, slower than the XS, loads the same or even faster than on PS5.
You add 2+2 and logic tells you that they have done something wrong on the XBOX platforms. That you want to ignore those details and also the general norm in 200+ games released during 1 year and a half (where there are many games that load even faster in XS) and you prefer to believe and make believe that ER is the example of the real differences and the rest is not worth..... OK, it's your choice and you should know the reason