Bring back the "Site Creation Template" to SharePoint online.
We used templates to generate many students sites on our on-premise SharePoint 2010/2013 servers so students would have the exact same site collection prior to class. Those templates are buggy on SharePoint Online and SharePoint online removed the save a site template by design so we cannot create a new one.
Use this command to enable 'save site as template'
Set-SPOSite -Identity https://[TENANT].sharepoint.com/sites/[teamsite] -DenyAddAndCustomizePages 0
We use two custom templates to create client and project sites, and now we have no way to improve them. Previously we could make our edits, go to Site Settings, and hit the Save as Template option. We're dead in the water and will forever be stuck with templates created in 2016. Ridiculous.