All I can say is that, based only on the comment (I don't know you at all, of course) you may be missing out on literally the best things in life. I don't think I've seen a long-term relationship that matches your description, I haven't read an expert describe them that way, and I don't think it would be healthy or tenable. Sex drives, for example, diminish as people age; and IME relationships primarily focused on sex don't last to become long-term ones. Another way of looking at it is that long-term relationships with prostitutes would fit your description.
Sex is great and valuable; it's probably necessary at certain points in the relationship; but it's certainly not sufficient or the most important thing. Love, intimacy and human bonding are far more rewarding and valuable (and all enhanced by positive sex). As another easy example, beyond a doubt anyone I know with kids would give up sex before they gave up their child; it wouldn't be a close decision - it would be offensive to suggest otherwise to them.
EDIT: I omitted a very valuable reason for long term relationships: To have someone to care for, for whom you matter. I believe research (and plenty of anecdotal examples) shows that, lacking this benefit, isolated people feel like they don't really exist.