Which is good, but may not apply. I have an application where I can't do that because we support plugins and so a couple classes will get overridden outside of the compilation (this was in hindsight a bad decision, but too late to change now). Meanwhile most classes will never be overriden and so I use final to saw that. We are also a multi-repo project (which despite the hype I think is better for us than mono-repo), another reason why -f-whole-program-vtables would be difficult to use - but we could make it work with effort if it wasn't for the plugins.