I assume there are too many .40’s out there for them to go away fast. Maybe in a few decades.
I’m likely to time out - I’m in my 60s - before the 40 S&W is. I’ve got one gun for it. Glock 27. Maybe it shoots a little harder than my Ruger EC9. MAYBE. Not enough for me to notice. I like the Ruger but feel better carrying the Glock.
But I carry 357 in my S&W Model 60, so what do I know?