There’s no point in having Leagues anymore, just have regional conferences.
Yes,the league distinctions have faded.
At one time, there were distinct identities for the old AFL teams and original NFL teams, which they tried to continue by having the American Football Conference and National Football Conference.
But nobody talks about that much anymore. How many people make note that the Chicago Bears were an NFL team before the merger? Or that the Patriots were an AFL team?
Then with expansion, teams such as the Carolina Panthers were never part of the pre-merger alignment.
Leagues will stick around because of playoffs. Likely another team will be added in each league, with each league having four 4-team divisions. And likely a reduced number of regular season games.
Regional conferences could work too, along the lines of the 2020 season. Less travel and greater regional rivalries.
It's just terminology - a difference without a distinction. Call them whatever.