Someone could tail you and follow you around and manually write it all down in a notebook.
They could, and then they could also be charged with stalking.
It's not just ease of collection. It's how the data is being retained, secured, and shared among a great many other things. Laws just haven't kept up with technology, partly because yeah 70yo politicians that don't even understand email but also because the corporations behind the technology lie and bribe to keep it that way, and face little consequences when they do so improperly or mishandle it. E.G.
https://www.cbc.ca/news/politics/cadillac-fairview-5-million-images-1.5781735
When the government does it, we seem to have even less recourse.