I used to miss PWP ceremonies a lot in my old town. I'd get too lazy and say no. Nowadays, in my new town, I make sure to go to every PWP ceremony, because I hate seeing Isabelle get so sad over you not attending something she deliberately prepared.
Only for relevant PWPs and that cerimonies make sense. So I did one for the lighthouse, the caf?, police station, campsite, etc
For benches or PWPs that are only there to avoid villagers moving in that area, nah. I also think I didn't do one for the bonfire, because it didn't make much sense for me. Sorry Isabelle ):