Thanks again for all the productive replies. Happyhusband's hyperbole is the closest to how I feel. I love my wife and don't think I'll truly be happier with someone else. But SamHam is right too -- I often feel like she doesn't desire me, and I want my wife to desire me. I'm sad that my wife surely has felt the same way.
I want her to feel happy enough and relaxed enough and confident enough to think of sex, but I'm losing hope that it will ever happen. She's too busy being a great mom and a productive person. In my frustration, I look at other women and blame my wife's physique, but I know it's more than that. In an oversimplification, sexual excitement may be = hotness x attitude. I'd like to constructively raise that product, and daily compliments seem like a great start. Then I have a problem: this line of thought is me trying to change her [priorities].
I'm the prime beneficiary of all her hard work. She's raising a great kid, taking care of our lives while I work, and she's spending a small fortune to make our house beautiful. I'm grateful, but I also care less about my surroundings and more about intimacy.
As a defensive aside, I obviously have flaws, but I don't consider myself an ugly person. I exercise 4 days/week and if you think hair transplants can't look good, take a closer look at Elon Musk or google Hollywood hair transplants. My point is that trying to look good is part of my identity. This is true for many men and women, vain we may be. I understand why it's less important for my wife than it used to be, but I wish it weren't.
Also, if my thinking sounds too strange to be real, just check out INTJ weaknesses ("romantically clueless"). Overly critical? You betcha. Of myself too btw. It's helped me in many ways, but I sometimes struggle and overthink.
But the problem with the bold above is that you weren't happy with her back when, either. Which means that even if looking good were more of a priority for her long ago, her prioritization didn't make any difference. You still weren't excited by her, were looking at other women and even expressing your dissatisfaction with her. Apparently, her placing a higher priority on looking good still didn't make her good enough in your eyes. And the worst part is, she knows it.
Which may be a huge part of the reason she doesn't feel happy enough, relaxed enough and confident enough to think of sex with you. You made it fairly clear early on that she wasn't doing it for you. She knows you're not really into her, sexually, even though you probably want sex. She feels unsafe, emotionally, being vulnerable with you. Which has, naturally, negatively impacted her sexual self-esteem and your sex life together.
There are other things in her life that do make her happy, relaxed and confident, and those are the things she prioritizes. Those things just aren't you or sex with you.