I'm not sure if it makes it fairer, but it makes the game different.

Theoretically, the game starts as fair. All start with the same money, on the same place on the board. But since you move by rolling dice, some folks get luckier than others, with more chances to buy things or gain income.... or simply avoiding landing on a built up property. The free parking money basically puts lottery money into action. Sometimes, free parking is funded by fees (jail fees, cards, etc) and some folks just take moeny from the bank and put it in the middle.

At times, it means the rich get richer. Sometimes, the poor pull themselves up. Many times, it just makes everyone richer at different times and it takes a lot longer to make folks go bankrupt. It does give a little chance of winning something with each go around the board, and I think this is why the rule is popular.

no, it just prolongs the inevitable. The first player to gain an edge on the others still eventually wins, it's just that it takes hours instead of minutes.