Thank you for your feedback. For now, you can use an API through Powershell to import .mpp files in Project for the web. You can learn more here: https://techcommunity.microsoft.com/t5/project-blog/import-project-desktop-files-to-project-for-the-web-api/ba-p/2031298
We are also looking into other ways to support import. Stay tuned for future updates.
An error occurred while saving the commentBob Dobbs commented
Why is it that every other web product Microsoft makes works alongside the desktop product other than this one (Excel, Word, PowerPoint, Visio). What is there to think about? This should be table stakes.