SharePoint without Sync (Advice Needed)

Our biggest challenge with SharePoint is how to roll it out to End Users with no SharePoint Experience (many of these users are engineers/site based on slow(ish) internet connections.

We have large (+100,000) document libraries with long paths. 

Sync has been a massive issue, the default behaviour has been to just use File explorer to access files, resulting in sync errors and accidental deletion of files.

I am looking for advice on turning OFF sync (in the document library settings)

• I have concerns about doing this, as there are always times when it is easier to Sync, and this is essentially a global setting (set for all users)
• Has anyone had any real life use cases/experience of doing this.

I cannot think of any alternatives.