@rsignell-usgs mentioned that that are already a lot of standards / catalogs / services etc. in this space. It would be useful to enumerate these so we don't go about re-inventing the wheel too much.

I'll kick things off by linking to @cholmes's blog posts about why they decided to invent STAC:

• Announcing the SpatioTemporal Asset Catalog (STAC) specification
• The Potential of SpatioTemporal Asset Catalogs
• Static SpatioTemporal Asset Catalogs in Depth
• WFS 3.0 and SpatioTemporal Asset Catalog (STAC) in person collaboration - in this he notes "Like many I have been skeptical of the direction of OGC standards as they’ve become bigger and more out of touch with modern software development."

A STAC Static catalog:

A static catalog is an implementation of the STAC specification that does not respond dynamically to requests - it is simply a set of files on a web server that link to one another in a way that can be crawled. A static catalog can only really be crawled by search engines and active catalogs; it can not respond to queries. But it is incredibly reliable, as there are no moving parts, no clusters or databases to maintain. The goal of STAC is to expose as much asset metadata online as possible, so the static catalog offers a very lower barrier to entry for anyone with geospatial assets to make their data searchable.