The Americans neglected ground based air defences for three decades, insisting that expensive 5th generation fighter jets would handle all air defence. Let's face it, the US isn't at the cutting edge of SAM development, hasn't been for a long time.
Regardless, this is probably not the last Patriot Ukraine is going to receive. I expect them to receive a lot more, and promptly waste dozens of them against cheap Russian stuff that may or may not be decoys, and by next summer we will be talking about how the west is also running out of Patriot missiles to donate... (but not before the usual social media sites are bombarded with St. Patriot memes).
Bingo. I've said it before and I will say it again. The west could have totally reequipped Ukraines armed forces with cold war equipment that is in storage. Thousands of M113s, M60s, M109s, TOW missiles, M16s, UH-1s and so on. They have received less than 400 M113s. My own country has way more M113s sitting in storage awaiting the scrapman along with up to 76 M109s. They are outdated, but for sure better than a Toyota Hilux.
Ukraine currently operates the Airbus Super Puma. The UK has dozens of old Pumas sitting in storage. What do they donate? 3 Sea Kings! They could source an entire fleet of Pumas and Super Pumas from retired European stocks and the civilian market in no time, and the Ukrainians could use them with minimal training!