Trump criticized the Obama deal for failing to deal with Iran’s missile program and its proxies. The MOU says nothing about either.
Trump complained that the Obama deal transferred cash to the Iranians. The MOU contemplates immediate oil sanction waivers, an ultimate dismantling of the entire sanction regime, and the creation of an enormous reconstruction fund.
Trump said the timeframe on the Obama deal was too short. The MOU does not prescribe any timeframes or limits on future enrichment, leaving those issues for the Phase II negotiations. It is highly likely, based on the information to date, that the new timeframe will be consistent with the old one if an agreement is ultimately reached.
Trump demanded that the nuclear material be delivered to the US for destruction. The Obama deal’s requirement that it be sent to Russia worked. The MOU leaves the method up to further negotiation.
There was no war in Lebanon at the time of the Obama deal, so there was nothing to address. The MOU purports to end the fighting even though the combatants aren’t parties to it. Good luck with that.
There was no issue with the Strait of Hormuz at the time the Obama deal was executed. Trump effectively created one with his war. The MOU resolves the problem in the short run but leaves open the possibility that Iran will obtain more control than it possessed prior to the war.
Based on the foregoing, there is no reasonable argument that the MOU is a better document than the Obama deal, or that the war accomplished anything positive; the most important new development is Iran’s ability to shut down the Strait of Hormuz.