So based on a sample of one your diaphragm switch lasted approx 330k cycles. The original Wayne pump (Lowes used to carry WaterAce but switched to Wayne) had a diaphragm switch sort of piggybacked on it. Coincidentally, that pump lasted approx 15 months but failed due to the pump or motor seizing. As it also carried a lifetime warranty, I was able to exchange it. By that time the manufacturer had redesigned it to use a vertical float switch with a very short on-off differential. Replaced 2 in 8 months since.
So the diaphragm switch was still functional after I am estimating 125k. The turn on level did drift a little upward with time. Not a major issue.
I see ballvalve suggested a heavy duty relay. I have also considered wiring two external switches in parallel at different heights. If you have the physical space to do that, it gives the advantage should a float stick with debris or mechanically jam. I have also learned to test the backup once a week.
We have been in this house 10 years. Think I have replaced the pump 7 times.