1 Cycle is discharging from 100-0 and charging from 0-100, regardless of how many times the phone is charged, so for a user that averages 50% battery drain each day, 1000 cycles would actually be ~6 years. I have no idea what the actual average is, but I'm betting that 1000 cycles is at least 4 years for the average user and possibly significantly longer.

Cycles to fixed capacity loss vs. depth of discharge is basically a straight line in a log-log plot. The advantage of shallower cycles is exponential.

Cycles are not days. My 7 month-old phone is currently sitting at 55 cycles. At that rate it would take me ~10 years to reach 1000 cycles.

It isn't quite that linear in practice but realistically it will still be at least 5+ years.

My phone is from December 2023, so 28 months and is at 842 cycles (and 85% max capacity). So, about 33 months at this rate.

6-7 years for me on the current phone, double on the previous one. 7 years is a good limit.