I don't really see ARM as having an inherent advantage. The main reason Apple's ARM chips are eating x86's lunch is because Apple has purchased a lot of capacity on the next generation nodes (e.g. 3nm), while x86 chips tend to ship on older nodes (e.g. 5nm). Even so, AMD's cores aren't really that far behind Apple's, so I think the node advantage is the main indicator here.
That said, the main advantage ARM has is that it's relatively easy to license it to make your own chips and not involve one of the bigger CPU manufacturers. Apple has their own, Amazon has theirs, and the various phone manufacturers have their own as well. I don't think Intel would have a decisive advantage there, since companies tend to go with ARM to save on costs, and I don't think Intel wants to be in another price war.
That's why I think Intel should leverage what they're good at. Make better x86 chips, using external fabs if necessary. Intel should have an inherent advantage in power and performance since they use monolithic designs, but those designs cost more than AMD's chiplet design. Intel should be the premium brand here, with AMD trailing behind, but their fab limitations are causing them to trail behind and jack up clock speeds (and thus kill their power efficiency) to stay competitive.
In short, I really don't think ARM is the right move right now, unless it's selling capacity at their fabs. What they need is a really compelling product, and they haven't really delivered one recently...