[ghaff]

Freelancing in the sense of filing a 1099-MISC is quite common.

If you're a landlord, you'll be filing a 1099-MISC

Essentially any royalties, 1099-MISC

Have any sort of side business even if wholly unrelated to your job, 1099-MISC.

You get into any actual consulting work and, yes, it becomes more problematic with many companies, but still many do it.

I've very much been a full-time employee for essentially all of my career, and I've probably filed 1099-MISCs most years for one thing or another even without having been a landlord.