I think the bigger picture here is that sync in DT is far from seamless (and it seems worse in DT3 vs. DT2); IMHO sync should really be invisible to the user, and “just work.” …
I’m not sure what this is in reference to, as the iCloud monitor - again - has no bearing on syncing. Many, many people are happily working and syncing databases every day.
Also, you can’t reliably compare the sync in other apps as they are not doing the same thing as DEVONthink, from a technological standpoint.
And any remote sync location is not under our control (something I have discussed often), especially concerning iCloud syncing.