Hi Robert,
Thanks for posting in the community.
For now, I am afraid there is no out-of-box feature to insert form in Excel for Mac. To view all the latest updates about Office, you can go to Microsoft 365 roadmap and search the feature. As you mentioned, you can insert the form in Excel for Windows.
Based on the situation, I would like to suggest you send feedback to Microsoft via clicking the Help menu and choose Give Feedback. It’s the platform for us to hear your voice and improve our products.
Appreciate your understanding and patience.
Regards,
George