You can bank on difficulty rising. Even if btc price goes back to 20k, its a stretch to ever roi on a newly purchased s9
You really shouldn't say stuff like this, if you aren't careful someone might believe you even though you are 100% wrong.
People used to say that about the s7s all the time. An s7 at 10c power was profitable until about 3 days ago....the s9 will be making money for a long time to come.