Strawberry is still active. But I think you need Beets or Picard, as others have mentioned.
There are a handful of other tools that can help with sorting as well. I think Quod Libet and Ex Falso are available on may distros, I used to use Ex Falso for quick manual tagging and pulling in data from other sources.
As for the syncing, I couldn’t help you there. I have used Strawberry for this, for sure, but I tend to drag and drop to my DAP.