How can I convert .xlsx files directly to .gsheet format.
Converting Microsoft Excel Spreadsheets directly to Google Sheets Shortcuts (.xlsx to .gsheet conversion) is not possible, and doesn't make much sense, since .gsheet files are only links (shortcuts) used to open a Google Sheets spreadsheets stored on your Google Drive. These files do not contain actual data, only references and Gmail account data used to generate the spreadsheets.
Every time an Excel spreadsheet is imported to Google Sheets, a new shortcut file (.gsheet) is generated.
Spreadsheet web app from Google
A popular spreadsheet application distributed with Microsoft Office suite