No way! I've only ever been the one being changed. And I'm not ready to have a kid yet; I'm still practically a kid myself. And I've never been in a situation where I've been around a baby relative who needed a diaper change. I mean, I've been in lots of social family gatherings in more recent years where there were infant or toddler cousins of mine around, but I don't recall a diaper change happening any of those times.
Yuuuupp! A ton of times. Excluding myself and actual babbehs~! I've changed a ton of diapers. My exdaddy wore on a rare occasion, though being involved in events and munches has introduced me to littles. Which in turn is how I met my BFF and she's become my little. So.... iunno. It's fun stoof.
Excluding myself, I've changed a couple other ABDLs (never changed an actual baby). I'm not that good at it, and am usually the one being changed. But it was good to try it, and help out some fellow ABDLs.