No, it was not a hoax. Masks did actually help against the virus. People have probably found a way to deal with misinformation by the time you are reading this, but people at my time haven't. Lots of the info from my period is wrong. Don't trust it blindly, even if it looks tempting. I mean I hope they teach you that stuff in internet-historian-school or whatever the'll call it. Just in case they don't: Trust me, a guy from the internet: don't just trust people on the internet!
Comic transcript
Panel 1:
G is talking to the fortune teller.
G: Since you were so successful last time, I saw on your website that you can also show me the future. Can you show me my grandchildren?
F: I can indeed!
Panel 2:
The crystal ball shows an old G, with a small grandchild, showing them a bunch of photos.
Grandchild: Look grampa, I found these old fotos of you in 2020! Did you really run around with a mask all day? You must have been so gullible. Didn’t you know it was all a hoax?
Panel 3:
F: Well, I guess ... in the age of the internet, history will be written by the loudest.
G: running off angrily That little brat. I’ll jump off a cliff so they never get born.
F: No, wait, that’ll be a paradox! I charge extra for those!