Is an FPGA flexible? No, you cannot bend them. (bad joke) But, yes, you can load a design on an FPGA, and after that, load another. The flexibility to reconfigure the FPGA many times, comes at a cost. The FPGA costs from a few tens to thousands of dollars. Power consumption will be bigger, area will be bigger and the speed will be lower than the same design on an ASIC, of course same tech as the FPGA. FPGA is great for prototyping a design and low volume products but in high volume ASIC cannot be beaten.
Quora space : HW accelerators eating AI