It should be possible to "save teamsite as a template"
To save a site as a template used to be so easy! But now you need to be a developer to do this for modern teamsites or communication sites! Why??
Thanks for your feedback! Although we appreciate your time and effort to give us this feedback, it’s not something we’re planning to do right now.
Classic save site as a template capability was designed in away which is no longer valid implementation style in the cloud.
We are in a journey with the Site Designs and Site Scripts potentially provide end user driven export capabilities, which could be used to achieve similar outcome, but we are not planning to provide classic “Save site as a template” capability in the modern SharePoint sites.