Indeed the difficulty jumps seem to be lower and lower.

Also you might be able to sell the miner after. Or use it as a heater  .

I think those will ROI by a small margin if you don't pay a huge amount on electricity. You would need quite a few of them to make a nice profit though.

But there is nothing really appearing on the horizon to compete with those...maybe a 1.8-2.1k 1TH miner.