5 players, 3 lanes providing constant resources (xp, gold) and a jungle with more respawning resources available to be taken.
You want your team to acquire as many resources as possible so they have as much power as possible in a fight, so you want at least one player in each lane to acquire those resources. It also makes sense to have at least one player farming the jungle for those resources. That leaves a fifth player, where should they go?
Teams generally need an adc to provide sustained damage in team fights and objective-taking power, and adcs generally benefit a lot in the laning phase when they have a support helping to zone enemies into that sweet spot where the adc can keep up damage with their ranged autos or at least stay safe while being close enough to the minion wave to cs, they also scale more with gold and items than levels so a support letting them take all the cs doesn't really cost them very much, so the adc/support lane makes sense. Where should that duo lane go?
The three objectives in the early game are towers, dragons, and rift herald. Towers exist in every lane, but they are closer together in the mid lane so a champion attacking that tower is safer from ganks because they don't need to travel as far to safety (also if they have to back they don't have to travel as far to get back to lane so they miss fewer resources). Rift Herald provides a buff that is much better when a champion is alone so it is much more useful on a solo laner than a duo laner. This means a duo lane would provide more use in the lane closest to dragon rather than rift herald.
If there were alternatives to 1-1-2-1 lanes (other than lane swaps and australian lanes which are done to try and avoid bad lane match-ups or counter a predicted lane swap) then the closest would probably either be double mid lane so the team has a lot of roaming power to gank top or bot lane, or double jungle for a faster clear speed and powerful duo ganks. In both cases this means making a tradeoff of lost dragon pressure for unpredictable ganking power because bot lane will be pushed in by a duo more often than not.