XFL has ties to the NFL. I can watch an XFL game and see rules, innovations, and technology that the NFL is actively testing to potentially bring over. The USFL doesn't have those same ties. USFL will also get lesser quality players in all likelihood as the XFL has a partnership with the NFL in that area too (the nfl player development program or alumni program) where they're getting access to players already trained by the NFL and deemed "NFL ready", as well as access to the NFL's healthcare and nutrition programs...
To me there's just no comparison. USFL investors should have instead invested on expanding the XFL in 2024, maybe starting another couple of teams, rather than try to do their own thing...