What is the correct etiquette when you have workers/handymen in your home?

I have been doing a lot of improvments in my place lately and I have a lot of people coming in and out for building stuff as a result

I am working from home so I usually leave them to do their thing and lock myself in my room to focus on my work. I thought this was normal but some friends told me I was being rude and I should stand by the men as they do their thing.

But to me that feels a little invasive? Personally I get very annoyed when people watch what I do and try to intervene, is it different with builders?

Looking forward to what you think

PS: I of course offer them drinks/snacks or whatever they may want before I leave for my room, I have manners