Only there are some but what happens with most,cheating or divorce.
Lust is superficial, love is deeper. You can have lust at first sight because that's mostly what lust is, first sight. But you can't love someone without knowing them - meaning romantic love rather than unconditional family love.
Love is deeper. And yes lust can survive as a part of a greater love. Doesn't always, but does plenty of times and I would imagine does in most successful marriages.
It is not the same... Just, lust endures over the time and it doesn't fade.
This makes love survive forever.