If you want to share your Google Sheets Gantt chart with others so they can edit the file simultaneously, you won’t be able to do so unless they have an existing Google account.
If your spreadsheet information is stored across multiple Google spreadsheets, then you will need to use another method for creating a Gantt chart starting from each sheet separately.
Google Sheets can’t handle large data sets.
There is no specific format in place so your Google spreadsheet can quickly get out of hand if you have too much project data.
Compared to creating charts with an online chart maker, Google Sheets only allows you to create simple charts without many options.
Google Sheets may not be as accurate or customizable as some other online tools, free and paid, that offer more features.