Big part of why we began pushing for TLS everywhere is that ISPs were doing DPI to inject ads in web pages. There's very real precedent for this stuff, and a real market for selling information on your web habits as well. Besides the obvious value for the spooks.
replyIt's taken a conspicuously long time to even begin to see a solution to the glaring privacy issues with SNI. Even just counting the length of time we've been aware of the problem of SNI being used for censorship and eavesdropping[1], it's over a decade, and ECH's is status is still very experimental in most web server software (and ECH is kind of a janky hack even after how long this has been discussed back and forth, the ESNI debacle, and so on).