According to polling most Americans support stricter gun control measures but not a ban. As usual, it’s the Electoral College and FPTP (IMO, no country with either should be listed as a full democracy. Not USA, not UK, and not Canada.) Still, it is true that the gun issue is too often presented as binary (but I’d actually say this is just as common with foreigners arguing for gun bans as it is with Americans arguing against it.)
Guns are pretty much banned in Japan and the UK.
Still, presenting it as a binary is harmful to the movement, when Americans regularly poll in favor of stricter gun measures but not an outright ban.