Google doesn’t care about the .html or nothing. They are all treated the same by Google bots. And they index the page and rank page equally without giving any preference to which extension is it saved.
Technically saying you will not benefit SEO if you remove .html extension. Even I don’t remove these extensions from this website HtmlSave.com
I help people to save and host Html codes or documents on this website. And I provide a rendered .html URL to the user. You can also try this. It’s for free and you don’t need to register for anything.
I hope it helps. Thanks!