LibreOffice Calc can do this already.

The main issue is the collaboration aspect of LibreOffice. I imagine though with funding LibreOffice can be upgraded to do this. If countries are already trying to migrate away from US tech, they could invest in this.

I know actually that LibreOffice specifically has lamented xlsx, apparently it’s a hard file format to design for.

I personally think the future is a database like postgres or sqlite that is know to be very robust with a nice calc frontend. I believe Mathesar is on it. Watching them closely.

Why ? Because falling back to SQL for big data would ne just great. Excel and Google Sheets seems to struggle.

I think that's the wrong approach. No matter how hard or easy it is, Microsoft controls it and do you'll be putting huge amounts of effort forever, whereas they can break your stuff with little effort. Losing battle.

the spreadsheet part is done already. the real power of excel these days is M365 cloud integration.

Gsuite and Zoho try to compete but they don't come close.