skipping auctions, and having money in free parking are why most people think monopoly takes a long time to play. It's like playing musical chairs but not removing any.
In part, but it still takes a while to play, and the outcome is obvious long before the end, leading to an anti-climatic slog at the end. This happens even if you play by all the rules.
"I got 6 hotels and half your properties are mortgaged. Let's play for another 15 turns until you happen to land on my hotel, then I will win."
I have often had uncertain outcomes at the end. For example, I had orange and red Monopoly with houses; the only other Monopoly with houses was green. Advantage was clearly to me. The third opponent bankrupted on green, I got the real estate tax card, forcing me to sell three houses right before my lone remaining opponent ran my gauntlet, then I hit green, jail, green again.
"I got 6 hotels and half your properties are mortgaged. Let's play for another 15 turns until you happen to land on my hotel, then I will win."