It would be inaccurate to call Saudi Arabia one of the United States' most important allies. The reality is that this relationship is incredibly uneven, and the US often puts the interests of the Saudis above its own. The country's repressive regime, questionable budding relationships with Russia and China, and history of funding terrorism and starting humanitarian crises are all reasons the US should reevaluate its relationship with the Kingdom.
Saudi Arabia is an important U.S. ally and is an important economic, diplomatic, and security partner in the Middle East. Maintaining this strong relationship is critical for global security, and while the US may not be able to stop the developing relationships between the Saudis, China, and Russia or the resumption of talks with Iran, it can help to influence the nature of these relationships and ensure they don't become a threat to American interests. The US needs to approach its relations with Saudi Arabia focusing on the bigger picture and looking towards the future instead of focusing too much on the current geopolitical situation in the region.