Are any web features not available in browsers when using self-signed certificates instead of mkcert for local development?

So I know mkcert to generate certificates when one needs HTTPS for local development (e.g., HTTP2). But would a self signed and temporary accepted certificate be enough? Is there any difference once it is accepted? Are all web features available in both cases in all browsers? I.e., is security context the same? I noticed around some hints that this is not so but I could not found any details what exactly would not be the same.