I find the convenience of Nextcloud to sync these things over the network to be preferable to over USB personally. From what I’ve seen there’s no simple gui method currently to sync over USB and instead this would involve the command line at least in part.
Also, Nextcloud can be used with Android to sync all of those things without syncing them to Google.
Will someone build a gui front end for that command line sync process eventually, probably. But I don’t think it’s going to be a high priority for a while.