Like changing your toothbrush, razor blade, or shoes they don't last forever.

when I change my underpants,, once a year,

Never had the need to change mine so far, couple of years.....

I change mine every million feet flown.

Only changing when damage occurs. Check boefore every flight for cracks or tips being damaged. I carry a spare blades with me on holiday, but never needed them.

When I’m putting the sunflower oil on the motors ;+):::::

My pictures don't come out as sharp as they used to anymore..

Hi. Thank you for reaching out to DJI Forum. I hope that our valued DJI co pilots can provide you the best information for this inquiry. In addition, it is recommended to replace the propeller when you see damages like cracks or deformities on the said propellers. Thank you for your valued support.

DJI Paladin Posted at 2-28 09:05
Hi. Thank you for reaching out to DJI Forum. I hope that our valued DJI co pilots can provide you the best information for this inquiry. In addition, it is recommended to replace the propeller when you see damages like cracks or deformities on the said propellers. Thank you for your valued support.

At least setup some e-mail warning of how long a ban is going to be.  I thought I would never get unbanned so I cleared and blocked cookies (had to research) so I can keep coming in.  I saw someone post on a thread I've made way back and saw I wasn't banned so I came back and saw it was only 7 days.  Some people may never ever come back but they aren't as valuable to come back as me. : )

I have Mavic 2 Pro from August 2018, still use first set of props. Looks like new.