You undermine your own argument. Ukraine's admission was never going to happen anyway, and everyone knows it. Putin also knows it. So that isn't why he is invading.
Arguments about NATO membership or repressed Russian speaking minorities and anything else (you get different justifications for the war depending on where you are in the world...) are fig leafs to exploit people's existing opinions of particular parties (in your case, about the US throwing its weight around).
The reality is far simpler: Putin wants the Ukraine personally. His own private reasons are irrelevant. He wants it. And he has the will and capability to take it. And so he is doing so.
I'm going to pick one one part of your statement in particular:
> US and the EU should've realized the only way to defuse this situation was to negotiate
Putin wants Ukraine. Negotiation of any kind was never going to prevent this invasion, unless the concession surrendering without a fight and having Putin install a government of its choice.
This situation is anything but simple.
Example 1: Russia invading Ukraine is powerful evidence to any other country that they need to join NATO for protection, most notably Finland and Sweden.
This is somewhat similar to one of the many problems with the US invading Iraq. It told the rest of the world that the only way to gurantee their safety was to have nuclear weapons. Putin's move drives neutral parties to NATO.
Example 2: while the EU in particular is unwilling to hit Russian energy exports, that situation may change with prolonged Russian aggression.
Example 3: the Russian invasion of Ukraine is deeply unpopular in Russia. Thousands of Russian protestors have been arrested already.
Example 4: Ukraine is a country of ~44M people. Russia cannot possibly hope to hold it. The insurgency cost will be enormous. Attempting to hold Afghanistan in the 1980s had a massive cost for the USSR and was arguably a contributing factor in the USSR's downfall (along with many other factors to be fair). Even if Russia simply plans to install a pro-Russian regime, that's not that dissimilar to what happened in Afghanistan. Occupying Ukraine would probably take hundreds of thousands of troops on an indefinite basis and have a massive cost in resources and lives.
> Putin wants Ukraine. Negotiation of any kind was never going to prevent this invasion,
That's basically the "trying is the first step to failing" School of Diplomacy. There are two broad possiblities: either it could defuse the situation or it couldn't. If it doesn't, then there's no downside to trying. In fact you get to occupy the moral high ground of at least trying.
That's the reason it won't put troops in now (and the reason anyone asking for that now is insane), but that wasn't the reason it couldn't put troops in 4 months ago.
Note that Russia is about to border NATO across its entire eastern border. This puts two nuclear powers directly staring eachother down at a border.
If Russia grows truculent over, say, Estonia, it's unlikely that the US response will be withdrawing troops from it.
Sanctions against Russia are completely ineffective because the US and the EU are unwilling to include things that would actually hurt Russia, namely access to the financial system (ie SWIFT), energy exports (because Germany in particular is dependent on Russian natural gas, the assets held by Russian kleptocrats).
On the security front, the EU woulld never accept Ukraine as a NATO member and the US won't put troops in Ukraine because that would put nuclear powers in direct conflict.
So given no effective sanction options and no military options, the US and the EU should've realized the only way to defuse this situation was to negotiate. Yet Biden categorically ruled out the possibility of formally refusing to admit Ukraine to NATO, something that was never going to happen anyway.
This situation bears some similarity to the US and Japan pre-WW2 actually. The US moved to block Japanese access to oil. That made war all but inevitable. I'm not saying the US was wrong there but it's just a consequence of that policy. LIkewise, leaving the door open to an anti-Russian military alliance expanding to the borders of Russia put Putin in a corner. Putin is still in the wrong here, straight up. But the options are to deescalate or World War Three. Given the invasion it's not much harder to negotiate out of this but what other option is there?
One thing I will say is that on the issue of seizing assets of Russian kleptocrats, real estate has long been a way of hiding money in developed countries. London real estate in particular is awash with Russian money. Maybe it's time we end anonymous ownership of property.