The Microsoft 365 substrate now captures Teams app card data in compliance records to make the data available for eDiscovery, content searches, holds, and retention. The compliance records are stored in user and group mailboxes. Audit records for card interactions are also logged in the Office 365 audit log. Using compliance records means that some app data context is lost, but at least you can find the information.
Project Moca is a new Office 365 personal productivity app which doesn’t have a mobile app. It’s hard to be productive if you can’t be when mobile. Which is why To Do allows people to capture thoughts. A workaround of sorts is available through To Do tasks. Whether this is enough for you to switch to Moca is debatable.