Can a Scrum Master be effective when working mostly remotely?

First I want to point out that a Scrum Master does nothing to manage everyday work other than their own.  

Second, I have worked remotely as a Scrum Master that was remote from my team.  It is a bit more difficult but it can be done.  I did all my communication via email, phone, instant messaging with an occasional video meeting.  The Developers and Product Owner were all co-located in a different country. I was doing this as a short-term assignment while a decision was being made on whether to relocate the team or keep them remote. I was still able to concentrate on the duties that are outlined in the Scrum Guide for the Scrum Master.  

I could watch how the team managed their Backlogs (Product and Sprint) by watching the flow of items through the process that the team had created. I asked questions to clarify anything that I was able to see.  I participated in all of the Scrum Events via phone or video call. Just because you are remote does not mean you are completely cut off.  BTW, all of this was pre-2020 where the world got comfortable working remote due to Covid. 

Remember that a Scrum Master is not a manager. We do not have to be intimately involved in the team's day to day work.  We are more concerned about their ability to understand and respect the Scrum framework's ability to help them be more adaptive.  

hololens from microsoft VR glasses is a scrum team solution to work remotely

VR glasses can be a solution to increase close collaboration and therefore trust at some stages

How can you manage everyday work, retro, and sprint planning?

Don't.

Or perhaps you have noticed your team is more productive and achieves better results when working remotely?

Remote or otherwise, I've noticed that teams are more productive when they manage themselves.

Best thing: shine a light, and take care to reveal rather than resolve.