We don’t fly Biden flags because we don’t want our houses burned down. We don’t put Biden bumper stickers on our cars because we want to avoid becoming targets for road rage.
In real life, I felt it slightly risky to have the US flag in front of our house, and I have eschewed political bumperstickers since the Carter years because I don't want my car vandalized. OTOH, I have seen some - a few - Hillary, Obama, and Bernie bumperstickers in my peregrinations about the SF Bay Area ... not one of which or the car its on having been vandalized. I think I've seen 1 or 2 Biden-Harris bumperstickers in the past 4 years or so, again, no sign of vandalism, but the rareness showing that while my county voted ~75% Biden, it wasn't with anything like enthusiasm.