Web-only access to iCloud lets you share and collaborate with others in real time on documents, spreadsheets, and presentations, even if they don't have access to an Apple device. That means you can invite anyone to share a file. Then they can use their web-only account to access the file and make edits, without leaving iCloud.”
I don't know about those other things, but Pages is horribly and notoriously incompatible with anything except itself. You can't share a Pages document with a Windows or Linux user, or a non-Pages user for that matter.
I don't know if Pages has robust export capabilities, but if Apple wants to compete, they had better start blatting out compatible file formats by default and stop with the vendor lock-ins.
“What is web-only access to iCloud?
Web-only access to iCloud lets you share and collaborate with others in real time on documents, spreadsheets, and presentations, even if they don't have access to an Apple device. That means you can invite anyone to share a file. Then they can use their web-only account to access the file and make edits, without leaving iCloud.”