Yes, cause sex is a nice benefit to a relationship, however I know many people who, from age and/or surgery are no long physically able to have sex, that still value and cherish their romantic relationships.
When you look at it, sex is a part of many people's relationships, but it is certainly not all.
Look at ski racing champion Jill Kinmont. She was a US national level skier and Olympic hopeful who became a quadriplegic from a near fatal accident. She had never had sex in her life before she was paralyzed, but went on to have two major romantic relationships (and probably would have one, if he hadn't died.) She had limited control over even moving her arms and hands, but still chose to be in a relationship.
Here marriage lasted 36 years until her death early in 2012.







