On the west coast there were definitely people wearing masks for smoke prior to Covid.
I did buy some hardware-store N95s to have on hand for smoke, after our bad smoky summer in 2018. Never ended up using them because 2019 & 2020 weren't that bad, and by 2021 I had better fitting N95s (the dome ones trap so much stale breath!).
Lots of the cloth masks with filter inserts that were sold early in the pandemic were designs created for smoke & smog.