For the past few weeks there has been lots of talk about HTML headings in web standards circles. Perhaps you've seen some of the blog posts, tweets, and GitHub issue threads. Headings have been part of HTML since the very first websites at CERN, so it might be surprising to find them controversial 25 years later. I'm going to quickly summarize why they are still worth discussing, with plenty of links to other sources, before adding my own opinions to the mix. If you're up-to-date on the debate, you can jump straight to the "Bigger Dilemma" section.
I was watching Rachel Andrew talk about CSS Grid Layout yesterday at An Event Apart. Grid is amazing and the day will soon come where it's a dominant web layout tool of choice. That day isn't here yet though, as no stable browser is shipping the latest version of the spec (it's behind a flag at best).
The good news is that, as of just a few days ago, the spec is really stable and has entered "Candidate Recommendation" status. Since all browsers have been developing against the spec, it's likely that widespread non-prefixed ready-to-go support will drop in all stable browsers fairly soon.
The bad news is that it will probably do-so without subgrid support, a point that Rachel underscored well in her talk.