I've seen quite a few pilots who smoke, and yes, smoking still takes place on long flights. On cargo flights, it's been a regular thing and continues to be, for crew to smoke on the main cargo deck. Rare to see it in the cockpit.
I have flown for charter operators who permitted clients to smoke on long trips; some clients booked expensive charters, rather than flying airlines, because they knew they'd be allowed to smoke on the trip.
Smoking is very hard on avionics, interior, and outflow valves, which control pressurization.
Back in the day, it was rampant.