Politicians only read Xitter or Facebook, but places like the fediverse or even Reddit are ignored. They should be made aware of what people are saying regarding their decisions. Email is practically invisible and dead for most people as they live on other platforms and nobody will look up the email of some the minister of agriculture. But if somehow we could just @MarineLePen @Orban @KajaKallas anywhere on the web and they'll get an email in their inbox, I wonder what that would do to public policy...
They don't actually read their mail anyway, it usually goes to a staffer. At best, the politician gets a summary like "X real emails, Y auto emails, generally bad vibes on CC". Even the reply will likely be written by the staffer (if not auto generated entirely).
Email still has an important role for professional communications. Contacting your bank or lawyer or any company in an official capacity is usually done via email. This was true of fax in the past which was killed by email, but there really isn't a replacement for email yet.