It does add a "tax" of sort in the form time or attention that must be paid to keep a website up. You can't just sling some files in a directory and be done -- you have to pay for certificates or pay (in time and executable capability) to keep LetsEncrypt up to date.

And, as wonderful as LetsEncrypt is, it's not forever. At some point, they're gonna' get tired of messing with it or it will get taken over by private equity (see .org) and for whatever reason, it won't work any more.

And sure, that's always been true, new stuff obsoletes old and things fall by the wayside. But my current browser can access modern websites as well as sites from the dawn of the Web. But FireFox 85, 87 or 90 will probably make https mandatory -- and that amazing continuity is gone.

You cannot say that certificates are reliably free (especially in the long run), if there's only one entity providing them and that entity is dependent on corporate sponsors.

Not everyone needs HTTPS, in spite of what the HN mantra says.

Some websites are the equivalents of billboards.

The cost is dependence on a central authority that can make your site inaccessible in a whim.

Self-signed certificates are first class citizens. Section 4.2 of the spec.

The problem isn't just HTTPS, it's the ever-expanding array of various APIs and technologies that "must" be implemented to be a "real" or "complete" browser. Even Firefox, that's been around for a long time and has a fairly large mind share, is at best an afterthought in many web projects.

The amount of APIs that need to be implemented to be considered even a basic web browser is so huge that it's not an approachable project for just about any organization, and as an individual it's just not possible.