You're assuming NATO is somehow critical for the US. It is not.
NATO is critical for the European powers (those not named Russia). The US doesn't require it. The US doesn't need to defend Europe any longer. And it's clear the Europeans don't want the US there, so it works out great. Europe can boost its defense spending by ~$300 billion to make up the difference, or not, whatever they choose to do is up to them.
The US had the world's largest economy six decades before NATO existed. China is growing into a superpower entirely without a NATO-like participation. NATO is primarily beneficial to European stability. The US doesn't need NATO to defend itself at all.
NATO is critical for the European powers (those not named Russia). The US doesn't require it. The US doesn't need to defend Europe any longer. And it's clear the Europeans don't want the US there, so it works out great. Europe can boost its defense spending by ~$300 billion to make up the difference, or not, whatever they choose to do is up to them.
The US had the world's largest economy six decades before NATO existed. China is growing into a superpower entirely without a NATO-like participation. NATO is primarily beneficial to European stability. The US doesn't need NATO to defend itself at all.