Nobody pays into NATO, the chart which OP keeps posting every day shows federal military spending by country. That means for most countries it excludes the larger portion of the defense spending, which is local. This is why all of Europe handles natural disasters well, but every time FEMA shows up in the US, it turns into a shitshow.

NATO would collapse because it's obsolete if the US leaves, because EU itself could take over the administrative bit, if only EU/EEA countries cooperate in terms of defense. In terms of funding, nothing would change.

Notice how Elon doesn't want to audit the military industrial complex. DOGE audits everything, even the treasury, but not the military industrial complex which is actually wasting a lot of taxpayer money.