1. I don't know how my employees are doing; many times in my career I've had to tell programmers to "go for a walk" or "time to go home" when they get stuck on a frustrating task or fall in to a flow state far past leaving time. Solutions I've found to this put onus on the employee or create more restrictions that hinder in other areas
2. Brainstorming whiteboard sessions are harder; the issue with remote meetings is that you need each person to finish speaking before the next person can start, which IMO slows down collaboration. Also I still haven't found a great tool to replace the whiteboard, Miro / Figma (Figjam) come close but also are slower at spinning up a flow diagram or sequence diagram or describing a stack.
3. Juniors / Grads need handholding; I've written frameworks to train newer developers in a remote setting but the remote divide creates an invisible barrier between the seniors and juniors for base support. I used to purposefully sit them next to eachother to enable the quick "do I use this or that?" questions or, better, have the senior look over and spontaneously create a learning opportunity related to whatever the junior is doing.
I guess the themes here are speed and spontaneity
(I haven't had my coffee yet so I hope above made sense)