Lanes are belonging to one track. With track versions you can chain several tracks with the the same track version id and switch them together, with one key command. So it is easy to check alternative versions of a bridge for example.
Say you record multiple takes of a singer and then comp that into a single performance. You’d use Lanes for that.
On the other hand if you wanted to try out having your bridge go into a chorus or the bridge go into a verse, you’d use Track Versions for that. Or if you had two different chord progressions, use versions to switch between them.
Also versions can be renamed to indicate what’s on them, Lanes can’t.
Record a number of takes, into various lanes if so desired.
Immediately after I create a duplicate track version and work on the duplicate ONLY, let’s say I comp those takes.
I then use new duplicate track versions incrementally after each major editing operation (pitch correction, trimming, sliding, etc.). That way I’ve always got one version untouched by the last editing.
Before track versions I used to park a lot of tracks in an ‘edit’ folder just in case I would want to go back. Way nicer as track versions as everything’s in place automatically.