It’s definitely worth practicing, and the earlier you do it in an interaction the easier. If I’m chatting with someone for more than a minute or two, or we talk about something more interesting than casual small talk, I’ll just extend my hand and say “I’m by the way.” It’s never resulted in anything other than them shaking my hand and telling me their name.

Usually they want my name to try to sell me something. Usually solar panels. Sometimes cell phone service

It's more difficult for people to address you if they don't know your name. If someone sees you again after your first meeting, do you want them to come up and say "Hey... you! What's up?"