Security through obscurity mostly, I don't know who continues to push the advice to block ICMP without a valid technical reason since at best if you tilt your head and squint your eyes you could almost maybe see a (very new) script kiddie being defeated by it.

I've rarely actually seen that advice anywhere, more so 20 years ago than now but people are still clearly getting it from circles I don't run in.

I don’t disagree. I am used to highly regulated industries where ping is blocked across the WAN