I know many people on this forum go every year and some multiple times per year.
We have only been four times and are going in September for our 5th trip but, I am in my 40s and my kids are college age adults now.
When the kids were little we couldn't afford it, and when we could afford it my husband was dragged to WDW so going once a year wasn't possible, he just wasn't going to spend every year at WDW. I don't blame him. As much as I love WDW for me going every year would get stale. Seeing other places is great too.
WDW is very expensive. It surprises me so many can afford to go multiple times a year. My husband has a very good career, he does very well financially and we can't afford to take more than one nice vacation a year, which to me is a WDW trip.. Gone 10 days, roughly several thousand dollars with Universal.
Some are very blessed to get to go every year or multiple times. I know so many people who go once and that's it.