"A naive solution is to download and store the entirety of Wikipedia; then, all your queries can be local and the server never learns anything. Unfortunately, this takes a lot of bandwidth and storage (~10 GB), so it isn't very practical."

We can pretend this is a large amount of data but that notion becomes less believable each year, as bandwidth and storage capacity keep increasing.

Many of us now stream (=download and throw away) much more than 10GB on a regular basis.

Local databases, where queries never leave the computer or the local network, exclude much of the "tech" industry that survives on monitoring and manipulating computer users through the internet. One would expect strong opposition from "tech" enthusiasts to any suggestion that a computer user can perform work or recreation offline.

"Tech" companies may not be the only ones. There is also that pathetic term "go dark" which hints at more surveillance being done through the internet.

If the computer user disconnects, it leaves many parties high and dry. Spending more time offline might not be a bad thing.