I have to say that the more I use 2016 to manage hybrid instances, the more frustrated I get. My customers tend to want some autonomy on self-management of users and I don't feel this split framework serves them well. I've been working with Exchange on-prem for like 20 years now and given that I'm frequently straddling both portals to figure out where things get done - and sometimes resorting to powershell because the gui just seems confusing - I just don't see how I can hand that autonomy to my client anymore.
I am annoyed that 2019 is still not an option and that I need to deploy a Server 2016 in the organization so I can run Exchange 2016, but at the same time, I'm really annoyed that we're halfway through 2020 and we don't have an option to eliminate that last on-prem management server, because even if 2019 was an option, it's still not a great one.