Consider that Sony is phasing out discs on January 2028 and beyond, meaning any upcoming game after then is no longer being released as a physical copy (neither will the future PS6 contain a disc drive at all) marking the PS5 as the final iteration within the generational lineup on having a disc. All versions of the PS5 inherit the same performance regarding games but the PS5 slim is compact while the PS5 Pro has a better CPU.
The only reason I can think of is if it’s the platform your friends are on and the games you want to play together aren’t cross platform or don’t allow cross play.