[Daegalus]

Well I do regular backups and they do ZIP nowadays.

And it's not Googles responsibility to make it easy for you to import to other services.

They use open formats and standards in their export. It's up to you and the other providers to mess with it. A lot of them can import directly from Gmail over API.

Mbox can easily be converted to maildir. Which can be used by thunderbird, not much, sup, etc.

I know people hate on Google but in this case it's not on them to make it easy. The fact that you can export it into open standards is all they have to do.

Finally, this is probably their way of creating a dark pattern. Especially for email. Export into an old, less used nowadays format.