Thanks for the suggestions all.
I don’t have/nor plan to buy the Steam versions of Age of Wonders Planetfall, HOI4, EU4, Imperator Rome. It could be whatever UWP wrapper the games have in being bundled for GamePass PC but my system loads/runs other non-Paradox AAA games quite fast (RDR2, Control, Jedi Fallen Order etc.)
By commenting that Steam versions of Paradox games are also slow, I am referring to ones that have the Paradox launcher before loading the main game like Stellaris, Crusader Kings II and are not 3D powerhouse games–these all appear to use the Clauswitz engine like EU4, HOI4 and Imperator Rome. While slower than other games, these take 1-2 minutes tops to load.
I own almost all the games of the non-strategy type from their brands page (Battlefield, Magicka, Surviving Mars) etc and my system has never run into anything that takes this long to load which is weird and off-putting.
Looks like the Clauswitz engine these games use and UWP file system encryption? Who knows?