Is it that much better than the food you could make at home? To me the exorbitant price has always been about the locale and the privilege of sitting there.
Oh, my goodness, yes. My experience was Alex in Las Vegas before it closed.
The food was, of course, excellent.
However, the wine pairing was phenomenal. Most of the wines were very good to start but putting them with the particular dishes made both of them amazing.
So, for starters, unless your house readily uncorks 8 unique, really good bottles of wine to pair with 8 courses, you are certainly getting something very different, at least.
Now, I will grant you that this was before the whole "It's more important to post my food pictures on social media than actually enjoy the food." So, things may have changed.
You get approximately half-portions, but it's still probably close to 5 glasses of wine. You will get quite drunk if you drink it all yourself.
However, being Vegas, you don't have to drive. So, even if you are a bit drunk, it's not a big deal.
At home I am limited in my skills and in the quality and variety of ingredients. In a restaurant (one where the chef actually makes food, not a place where it's microwaved, cooked from frozen, or just repackaged restaurant supply food), I get a skilled chef using many high quality ingredients which I cant get my hands on for any reasonable price to use at home.
I'll still avoid getting certain things at restaurants that I could make at home (many pasta dishes for example), but there are so many things I'd have a lot of trouble making myself.