Fact is I never take (or give) business cards. A "what's your name - is this you in LinkedIn?" is more than enough for me. We could chat about your fancy card but I'm definitely not planning to carry any around, from or to home.
I haven't met any techie so far not being in LI. Otherwise for the occasional driver or plumber I'd just get their number on the spot (if not already having it from their site). Worked fine for me for decades.
I deleted my LinkedIn account years ago, and I know a bunch of other devs who have done the same, or have just abandoned theirs and never use it anymore.
I'm not asserting that non-LI tech people are more than a minority, but there seem to be quite a few of them.
What about all those people who don't use LinkedIn?