> companies in the early stage ignore i10n completely and then eventually realize it's going to be a huge lift to retroactively support it

That's the correct thing to do. When you're first building a product you're trying to prove that it can and should exist: that you can get people to pay you money for it. It doesn't make sense to spend your time or money doing anything else.

Once you're successful then you know that people in one country like your product and maybe people in another company will as well. But until you know that, that's the only thing you should be working on.