PIREPS are not “a lost art” at all IMHO. I give them and use them almost every time I fly. I find that ATC actively solicits them often, especially at my home airfield (KLOU). The folks in the tower have been very helpful in finding ice free air between layers. Center sector controllers are great at finding smooth air in the flight levels. Most of this information is local in nature and transient. It doesn’t get “published” but is available “just in time” from ATC.
I do not frequently give pireps, but there are three situations when I try to get one out …. when weather conditions are different than forecast, cloud tops when climbing above a ceiling, and the altitude that I break out on an ILS.
I went to college in Tulsa, OK. I flew over a frozen lake one winter’s day. The lake was surrounded by homes, not at all in the wilderness. However, somebody had stamped a big HELP sign in the snow on the lake, like they tell you to do in survival manuals. Though almost certainly a prank, I called it in so that it could be checked out and so that other pilots would be aware of it.
On another occasion, my home airport ran out of fuel but the manager (since gone) wouldn’t issue a NOTAM to warn pilots we had no gas. The FSS wouldn’t do a NOTAM on my word, so I asked them if I could file a PIREP. They said sure, so I did that every two hours for the rest of the day.
You do not have to wait for adverse weather to give PIREPS. Even if it’s “clear & a million”, they are always appreciated! Since the closure of most of the FSS’s and the difficulty at times reachin FSS on the radio, PIREPS submitted by phone after a flight are accepted by FSS. Pireps are the best real time weather info out there. Instructors should make it a habit to teach their students to submit PIREPS on every flight.