The spoofing happens frequently and it's incredibly frustrating if you are the unfortunate person whose number gets spoofed.

My number got spoofed by a robo-dialer who called the ENTIRE +1 469 prefix. I received dozens of calls a day from angry people who got called.

I’m afraid my number might be used as the originator someday. Often when I get these calls, I keep them on the line as long as possible, feigning interest in whatever they’re selling. I figure as long as I tie them up, maybe I can waste a bit of their resources. Probably futile, but makes me feel better.

Except they might retaliate one day and set their outgoing ANI to my number...

I do the same. A few of them got very angry, yelling quite creative obscenities. Some were amusing and I had never heard of. I took it as a an enriching cultural exchange. But did realize they have my number and could do something like what you suggested.

It's a fun hobby to learn to swear in all kinds of languages. Russians are very creative in this respect.