I actually bothered to look up what the bestselling comics of all time are to see how One Piece (and Dragon Ball senpai) would fare and here they are.
It´s "only" No.4 but the top 3 of Superman (The sales have been down for the last 15 years despite being the winner), Batman ( 😀 ) and Spider-Man (Can i have my marriage back as "Renew Your Vows" was a bestseller) are from 1938, 1939 and 1962 while One Piece started in 1997. Only the 2 manga and Tintin represent one coherent vision too and One Piece also set another Guinness World Record this year.
To suggest a decline is to laught into the face of comic book publishing itslelf as the top 3 have been rebooted, renumbered and whatnot but Luffy sails on. Sadly.
I am not sure how the series can ever end as it became the main support pillar for Shueisha + Toei and i wonder how the inevitable Hollywood version will look like...

I also read EU/US comics and am a librarian.
Manga-Masters, My ANN-Lists + Imdb

Ack I'm torn. Also didn't know Horimiya was shounen. Always thought it was Seinen.

I'm here almost every day and I never saw the list. That's probably because I, like 99.9% of the people who've joined MU, never use the forum anymore. It does explain the teeny fujo odor all over the final selection though.

Maybe if you want to get a little more realistic set of final poll choices next time, stick the notice on the Releases page.

Most people think it's shoujo. Because you know, "only girls like romance."