It depends. The old school, round knob dimmers were awful. I mean they caused electrical and often mechanical noise as well. That is, you could hear the dimmer itself.
I own about two dozen Kasa smart switches and dimmers along with maybe 3 dozen LED dimmable lights and have not run into this issue.
OTOH, the first generation of efficient bulbs, the compact fluorescent were really bad for electrical noise, putting not only noise but DC on the line.