Iif you bring in professional players they will be subject to the Bosman ruling and they will have freedom of movement. Transfers will become a fact, and you will have Dublin, cork, limerick, Galway, Kerry, antrim (Belfast) maybe Waterford and Louth, maybe Meath Kildare.
In hurling probably no real difference, maybe reinforcement of the current top table forever.
It's fantasy though. Lone Ranger mentioned cork and Dundalk being pro, but they are only so on the basis of Europe in Dundalks case and a unique situation with cork. That's only two teams though, even if the others are semi pro the players go on the dole off season.
If this golden age was to dawn, the interest in such a restricted number of teams would drive inter county into a eating themselves destruction.
I feel what will happen is that intercounty carrers () will get ever shorter and players will be younger. If there is a true return to economic growth you will have more not opting full stop and you may end up with the best players in the club championships and the intercounty standard will go down and the product become unattractive.