Yes there was something wrong without hindsight. The USA was clearly not going to maintain a large standing army in Europe to enforce some treaty. And the British were quickly reverting to the pattern of "very large navy, colonial army plus a couple good corp". So Wilson should have known that his ideas would not be enforced over the long run by US troops. The UK should have know that like the post-Napoleonic era, it would need a group of reasonably happy nations and a workable balance of power. France should have know that it would have to enforce harsh terms on its own, if that was the path. And everyone knew the Soviets would be an issue, and that is why you see things like Joint USA/Japan operations in the Russian Far East.
And if you start here, you can get a better treaty. Obviously A-L goes back to France but nothing else. The reparations were too high. Keynes told the British as their chief adviser. Or you could have know that by the way it was calculated. Instead of using actual economic destruction in the war, the French also added the lost future productivity of wounded and killed Frenchmen. So pretty easy to get a smaller reparations. Also easy to understand the Germans can't pay in gold, so it is a small step to have the reparations in terms of coal, ships and other industrial goods. For example, the exporting of coal from the Saar would have been reasonable reparations when combined with the 'value' of the colonies. UK can still get the Navy plus some limited gold payments or goods transfers (dyes, chemicals, etc). Italy is out of luck since A-H fell, but there was not real reason to make Italy unhappy. Give Italy what it can hold in the Adriatic and some meaningful colonial concessions. Why not give Italy something like German East Africa. Or if not that, give Italy Tunisia, Give France something from the UK or Germany, and the UK can keep East Africa. A good old colonial swap.
So with just a few changes, we can get a basis of a treaty that will not wreck the European economy any more than the war did. Italy does not feel betrayed. Justified feeling IMO. Now we just have one more big issues, what to do with Russia. Obviously, no combination of Entente are going to conquer and hold Russia. Obviously socialism is a biggest remaining threat. So either France maintains a large army for the rest of time, or they need allies. These allies have to be A-H or Germany. A-H implodes, and I doubt you can put it back together by 6 months after the war, so we need Germany as a counter weight. This means limiting German losses in the east and/or allowing a merger with Austria.
It is not hard to get to the logic of a workable treaty. One really has to understand that if the treaty is harsh, then France alone has to contain the Soviets and potentially any nation the Soviets flip to their allies. So it is pretty easy to see where the treaty needs to go. We act like this is impossible, but after the Napoleonic wars, the terms on the French were actually quite mild. After the war between Prussia and Austria, the terms were mild. Same for the Crimean war. And even the terms for the Franco-Prussian war were mild compared to the ToV. It is just the pattern that existed for a few hundred years was broken, and the risk was realized in the maximum possible way with Hitler.