The typical flu is more like 24 hours on a hard surface. Clothing and fabrics, 2-3 hours. On the skin it only lasts about 15 minutes due to the enzymes in our skin! (Our bodies are pretty amazing.)
In looking into face mask information, the CDC says that most of viral infections in the public are do to contaminated surfaces, touching them with your hands and then the hands to the face. They said that masks are not very helpful, but wearing gloves, washing your hands, etc. is most important.
If you are in close proximity to the infected person (taking care of them), then a N95 respirator is critical.
As stated above for viruses on surfaces...they last longer on hard surfaces (or Swiss bank notes)...generally not viable after 24-72 hours except Norovirus (gastrointestinal, think “cruise ships”) which can lat a couple of weeks.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0027932
https://www.health.com/condition/cold-flu-sinus/flu-virus-live-on-surfaces
https://norovirus.org/norovirus-on-hard-surfaces/
https://marinevac.com/norovirus-solution/