I've removed all of the microdata from the web sites I manage. I'm not giving Google any information for free.
Google uses microdata to show information from web sites without people actually visiting the site. Google gets free labor. Publishers get squat. Adding microdata to content pages consolidates information with Google, hurting everyone else.
Google has billions of dollars to spend on scraping and searching and whatever it wants to do. It could mechanical turk the entire internet if it wanted.
I am not Google's free labor.
But you probably don't. Presumably because you rely on google to direct users to your website. I find it hard to claim that publishers get squat out of this arrangement when google is probably the primary method relevant users find your content.
Which to be clear, I'm not saying that website operators have any sort of duty to assist third parties in extracting just the useful part of their website. They obviously don't. They can make their website however they feel like. I just don't think the disdain of google over the practice of extracting and redisplaying content provided in a format explicitly for the purpose of letting people do that, is warranted. If you don't want to opt-in, that's fine, but google is doing nothing wrong by using data provided to the world for the general purpose of enabling them to do exactly what they are doing.
You presume incorrectly.
The sites I'm talking about have no advertising. They are not ad-supported. They do not rely on Google or any other search engine in any way.
There are other business models.
Many of those business models still rely on people finding your site (although there are exceptions)
However microformats potentially help others, because of Google's actions it is to a site owner's benefit to not provide beneficial metadata past a certain point, assuming of course they want visits provided by Google.
I recall that John Mueller recommended JSON-LD over the other options during a Google Webmasters office hours session.
Many of Google Search's Structured Data features primarily have JSON-LD examples.
The name seems unfortunate, though, as I thought that was "line delimited JSON"!
Google is doing what Bill Gates wished Ballmer would have done. Thankfully the Justice Department stepped in to save the fledgling web. Will they be willing to do so to save it this time around?
Google needs to be forced to abandon Chrome and AMP.
Android is way more nefarious than a web browser. And they give it away for free to device manufacturers. I almost wish for the old days where everyone had their own OS, monoculture is terrifying.
It also allowed mixing the presentation with the format. that meant people only had to maintain one copy of data, so its less likely to get out of sync, and people are less likely to forget to add the data later on.
Downside is you're using something not really meant to support the use case of annotating data, so it ends up being a bit hacky.
These things also did not come out all at the same time. Future techniques were partially made in response to microformats, just like (I'm assuming a bit here) that microformats were made as a response to SemanticWeb RDF-XML stuff.
I've been doing web development since the commercial web started and somehow this thing eluded me.