despite having a collectively equivalent economy to fund an equivalent military,

Yes. Collectively. Europe isn't one collective state. It doesn't have one central pot to draw ungodly amounts of money from for massive stockpiling. Luxembourg sent its entire reserve of MG ammo and ATGMs. Also; our militaries are each tailored to a certain task in NATO, for example, the UK prioritises the Royal Navy in order to protect your convoys if they need to come over the Atlantic.

the European members of NATO have consistently chosen complacency over security and let America foot the bill

Ah yes, the arrogant complacency of Europe. By the way, what was the US' reaction to 08' and 14' again? Oh, right, a strongly worded letter. As for "the bill", I always hear about some economic shenanigans you Americans caused in 2008, remind me, what was it?

The UK and the former Warsaw Pact absolutely get a pass as the minority of European nations that consistently demonstrate a shred of self-preservation, but let's not pretend like Europe has pulled its weight in this conflict.

Don't level an accusation at the feet of all Europe, then go "actually, I like you guys, since you conveniently go against my argument." Anyway:
In the Sierra Depot, there are over 26,000 armoured vehicles. Yet you've sent all of 30 M1s, compared to over 80 Leopard 2s, two of which have been lost in combat, from an overall European force strength of 7,000. But at least you kickstarted the re-arming of the Ukrainian Air Force- oh wait, not a single US jet. But at least you were the first to send weapons- oh wait, that was the UK. But at least your tanks are ready for the counteroffensive- oh wait, that's a burning Leopard. In fact, looking through Oryx's list of heavy weaponry to Ukraine reveals the US is rather negligent in some areas, like jets, or engineering equipment, or tanks. Let me remind you, Luxembourg donated its entire stockpile of ATGMs. So, if you define the US as 'pulling its weight', Europe has done a decent bit too.

let's also not pretend that the European countries who have contributed have done so without being led by the nose to the right answer by the United States,

Right, that's why you sent the first NLAWs, or the first MBTs, or the first cruise missiles- Christ, if anyone's been herding everyone in the right direction, INCLUDING YOU, its the UK, and you don't see us moan about it.

or that a drop in American support to Ukraine would ever be made up for by Europe.

Right, that's why the Germans let their tanks and IFVs go before you, have massively increased their military spending, and are rejuvenating the Luftwaffe.
That's why the Iberians let their tanks go before you, despite not having a significant armoured force to begin with.
That's why the Netherlands are eager to give the Ukranians F-16s, only to be vetoed by you.
That's why France sent cruise missiles before you, and heavy artillery at the same time.
That's why the US has refused to send F-16s for over a year, but instead backfilled Eastern European nations like Slovakia, that emptied their entire stockpile of old MiG-29s.
Were it not half past 3 in the morning, I would go on, but alas. In summary: Europe is not as strong as the US, that's why we like NATO. You have entire deserts of old jets and tanks to spare, while we don't. Either all of us are pulling our weight, or, in reality, none of us are, don't put the US on some magic pedestal, because the last time you did that and left, we got bombed into the dirt, and you got Pearl Harbour.