Value could have increased for many reasons having nothing to do with labor effectuated by either party.
The neighborhood might have changed, and now there are more restaurants. Or maybe it’s just considered more fashionable for intangible reasons.
The house could be on the beach, and Alice has decided to take up surfing, so values the location more than Bob ever did in the past.
And so on.
There can be an almost infinite combination of reasons why Alice may find more value in the property than Bob.
Edit: my previous version of this comment had Alice and Bob reversed.
Value could have increased for many reasons having nothing to do with labor effectuated by either party.
The neighborhood might have changed, and now there are more restaurants. Or maybe it’s just considered more fashionable for intangible reasons.
The house could be on the beach, and Alice has decided to take up surfing, so values the location more than Bob ever did in the past.
And so on.
There can be an almost infinite combination of reasons why Alice may find more value in the property than Bob.
Edit: my previous version of this comment had Alice and Bob reversed.