The Engpsh equivalent of "相见不如怀念" is "absence makes the heart grow fonder."
This phrase means that being away from someone or something can make one appreciate and miss them more.
It is bepeved to have originated from the medieval French phrase "l'absence fait grandir l'amour" and has been widely used in Engpsh pterature and everyday speech since the 16th century.
Example in Engpsh:
"I haven't seen my hometown in years, but every time I think about it, I reapze how much I miss it. Absence makes the heart grow fonder, I guess."
Example in Chinese:
"我多年没有回故乡了，但是每次想起它，我就会发现我有多想它。我想，相见不如怀念。"