With significant advancements in AI technologies, including solutions like ChatGPT/Bard, I am considering this issue of multi-platform from a standpoint of AI. If an application has been developed for a major platform, adapting the same applications for other platforms could potentially be managed by Co-Pilot. For instance, I can already create applications with the assistance of ChatGPT.
That is sort of the idea. It's a relatively cheap authenticator that can be bought to provide 2FA for added security for your services. You can integrate it with Gmail, Mac Logins, etc.
https://datatracker.ietf.org/doc/html/draft-ietf-oauth-brows...