[not op] Given that Microsoft/Apple/etc. aren't mentioned, G Suite has no real alternative other than Zoho (Note: nextcloud doesn't do email, so it's arguably not a GSuite competitor). This list would be better titled 'free/open-source alternatives to Google products' since excluding the other big companies extends past "de-google" and more into "open source living", if that's a good term for it.

Microsoft is absolutely a GSuite competitor and has arguably been in the space longer.

I moved most of my custom domain emails off Google some months back and onto Microsoft 365 and it's honestly a great experience.

Exactly, but this list makes it a point to not include other big tech companies.