I figured the days of people actually building Ethereum mining rigs with GPUs was over by now and that focus would be more on asic or fpga. I'm pretty surprised.
I think GPUs are still more accessible for the people.
The thing that I faced regarding FPGAs is that there are not many public bitstreams available for it. I even managed to find Xiling VCU1525 but the price made me not consider it. They wanted $3350 + shipping for it. Not to mention the import duty could have been so high.
I was never intrigued by ASICs. It increased centralization, newer models were sold after they were already mined by the companies who manufacture it, no sales support, less warranty span and they become paperweight just after few months or so.
So, In the end. I think, GPUs, CPUs are a much better investment for mining rather than the above two.
Yes FPGAs are very tricky. Specially if you cannot develop your own bittstream. There is very little software and if there is the dev fee is crazy, i remember last week buying 100usd worth bittstream for CKB nervous which at the time was doing about 20usd a day, and still it has another 10% dev fee in it. Which is crazy high if you compare it to current gpu mining software dev fees average 2%.
GPU seems to me always the best choice for mining. Yes the profit currently is just not there, but that could change very quickly. If it does you can build big farm in few days from GPU cause the hardware is easy accessible.