I'm not sure I understand the value prop. For localhost, you typically just generate a self-signed certificate that doesn't need to be trusted by everyone, as the dev can just add it to their local store. There are also other services that provide ACME certificates for localhost domains, basically what you do for free (I can't find a link to one but it was posted on HN recently).
If you need a trusted certificate for local dev, something like Cloudflare Tunnels is more valuable as you can have other folks access the service.
If you need a trusted certificate for local dev, something like Cloudflare Tunnels is more valuable as you can have other folks access the service.