This is a fun dumb question. The easy answers are, both are highly regulated by federal governments, both are overpriced for the technology involved, and both can waste a lot of someone’s time. Both can be used to commit crimes.
Both have the same effect of numbers on their perceived value. If nobody had a telephone, it would be hard to sell the first one. When you think everyone has a gun, you consider buying one.
What’s different is, volume of telephones increases their value to society as a whole. Volume of handguns does the reverse.