Hi zygot.
I started to have the same concerns as you when Intel bought Altera. The direction Altera went since it was bought by Intel all but confirmed my fears. And then, to make things worse, AMD bought Xilinx.
I don't know the future either, but the recent announcement from Intel calmed my anxiousness a bit. I commented about this announcement on my blog: https://fpgaer.tech/?p=561. We still need to see what capabilites and prices their "midrange FPGAs" will have, but it is still a ray of hope.
And furthermore, new players are entering the field (of them, I have read quite a few about Effinix, but there are others). So if the worst becomes true and the biggies abandon small and mid range FPGA applications, we can always hope that other players will fill the vacuum.
Cheers.