[Andrew_nenakhov]

I would very much use a product that would work exactly like Google spreadsheets, web and all, but would be self-hosted.

[magusor]

Have you tried collabora office and/or onlyoffice ? These could match your need.

[Andrew_nenakhov]

Yes and it is atrocious compared to Google Spreadsheets, unfortunately.

[magusor]

Yes, they are indeed not as streamlined unfortunately. Maybe ethercalc if you need something lightweight, but that's also not a real alternative https://ethercalc.net/

[ochrist]

I use NextCloud with Collabora Online (hosted and trimmed down version of LibreOffice). All self-hosted.