Admittedly, many life challenge become easier if you've got it made. Whether caring for children and other people, maintaining meaningful activities, social connection, charity, working on one's mind and body, investing in health and beauty, etc. Also makes it far easier to stay attractive and interesting for each other and keep the relationship vivid or even to reinvent if necessary.
Still there are enough counter-examples that tell me even with lots of fame and money it's anything but granted. When I was younger, the Beckhams' glimmer and glitter wasn't my thing. Yet after so many years of surviving as a celebrity couple - and appearing quite credible in that - I really like to express my respect.