I don't think you can improve Excel too much, but you could the ecosystem around it: Microsoft should integrate a package manager. Not something public, but something companies can privately maintain and publish packages to, that would contain common functions for their specific business.

If I could have a way to download a macro to a spreadsheet that would automate database connection for certain data sets, that would be huge, and since it'd be centralized corps could even have critical sheets functions managed by version control.

Mission critical excel spreadsheets run huge sections of large corps, we can discourage it or provide tools to better manage it.