When Xilinx end-of-lifed the 5v parts I bought a LOT of them I've still got a few left. In theory you can still find refurb'ed parts from China, which have a pretty reasonable chance of being the part # you ordered. Anything from there needs to be fully tested and burned in.
Design wise I've swapped over to the Lattice M4A5 which is still in production and classed as 'mature', but for how long is always the question, the price will go up in 2025 because the cost of the parts literally more than doubled since I last did a bulk order. I'm picturing one backyard fab still capable of running a 5v compatible process dutifully churning out parts
EDIT:
Well... looks like all the M4A5 parts have hit End Of Life, last shipment 27th Dec 2024.. end of an era When I run out of them it's back to building this stuff out of TTL (!)