People who last visited the USA as foreigners, did the Border Control ask you for your phone code?

No, because I didn’t have a phone in the 90s. This has been a thing since 9/11 and the patriot act, so I have been boycotting the border since the turn of the century.

I'm Mexican but I work in the US. I've been coming to the US since I was a few months old since I lived closer to the border. I've never been asked for my cellphone or anything personal. They usually asked for the reason to come into the country, evidence of said reason and (before my work visa) my ticket to get out of the country

That said, since a few years ago you have to tell them your social media handles when renewing your visa, and it has a disclaimer that omission can be grounds for denying the visa

No, I was there in February this year and they didn't ask for anything. Had my ESTA online and they just looked at my passport as any country. They did take fingerprints tho. First country I ever visited where they did that

Nop, but the scanners were really weary about my left foot. I got checked darn near everywhere they had a metal detector. Which were in really random places, like a restaurant and a school.

I haven't been since Jan 2024, but entry was pretty trivial. The only out of the ordinary was that they asked which airline I worked for - The border agent didn't know C1/D visas also pertain to shipping.

Oh, and ine time they wanted to check inside one of my bags as a dog found it interesting - turned out I had forgotten a food item inside.

Before I got my work visas (a bunch of them) immigration really didn't seem to care. I entered on a tourist visa with a plan to stay for a month.
"Purpose of your visit?"
"Business and meetings" (which is allowed on a tourist visa)
"For a whole month?"
"Yes"
It was obvious he wasn't paid enough to care. So that time I was technically an illegal immigrant, as I worked far beyond just attending meetings.