17PM here still at 100% health with 184 cycles. I charge nightly to 100% using MagSafe.
I think the keys are partially a battery quality lottery and keeping the phone cool. With the vapor chamber and I don’t use my phone a lot out in the sun it stays cool, which I believe keeps the battery healthy.
The degrading of the battery is also not linear, so my 100% could drop like a rock and then stay at a lower percentage for a long time too.