I've known of 2 couples over the years that I've known and thought, that is what a relationship should be.
The first was a couple who were having a baby together in their 40s. They'd both been divorced, but had found each other, and were blissfully happy. He died the year after, but... for that moment in time, I was envious of their relationship.
The second is a married couple that I worked with. They are genuinely happily married. She's a dumpy little thing and he honestly feels she is gorgeous and very clever. He's geeky but she totally respects and fancies him. I've known them for over 10 years and have never seen anything to dissuade me about how good their relationship is.
However, these are literally the only 2 couples where I've thought, that is a really good relationship. I'm sure most of the people I know who are married are happy together, but I see those relationships and would hate to be in them.
So YABU - there are plenty of enviable LTR around.
YANBU - most LTR are not worth having.