Correct me if I'm wrong, but doesn't this also mean that each one of our miners is expected to generate only 1/7.7 = 12% the amount of BTC it was expected to generate a year ago? With the diff increasing this fast it can't be much longer before the current generation of miners are no longer profitable without a serious jump in BTC value.
You are correct - difficulty rising means that, in order to stay competitive, you must constantly upgrade your farm and added more hash power.
However, no one can predict what the price will do. Even though they were very old, when the price was at $20k, some last gen miners were profitable to run even.