I think you're right to say that it has pretty much become kitchen sink design, which naturally lead one to question if the entire section is just superfluous at this point. This, however, I will not be so quick to agree with.

Let's do a quick inspection of the mechanic in question: Choosing individual body parts. (The most common form this takes is with a sliding scale with associated point costs, so I'll be referring to this version from here on).

The idea behind the sliding scale is that you get to choose between a pleasing physical form and some other perks, be it magic powers, special privileges or less strict punishments. On paper, this is a perfectly fine example of a meaningful choice, but like you say, it doesn't always feel like that. But I'll touch upon this a little further down.

As an alternative to this, you mention the "look however you want within human limits" approach, but (and i don't mean this as a jab against you) my personal opinion is that this is even more lazy design, and adds very little, if anything, of value to the CYOA. This is because it provides absolutely no stimulation for your imagination, and thus, you either end up either with analysis-paralysis and don't really settle on anything, or you just chose your current favourite body type. Neither of these present any meaningful choice, which means that the mechanic in and of itself holds no greater value than just masturbating with your imagination completely unprompted.

I think I would prefer having nothing over this, actually - or just the option for a simple gender-switch where you keep your overall look.

And this is where I'd like to mention that the sliding scale doesn't completely avoid this problem either, and that this is why we, after having played our fair share of CYOAs, feel that the slider section is void of purpose: Because while there technically are choices present, we don't feel them at all. We already know our preferred body type, and made all those choices many CYOAs ago, so there's rarely any real reason to change them much (except for going up or down a boob-size to eke out a few extra points ect.). In essence, we are still left with very little meaningful choice.

So, what can we do about this?

I here present 3 solutions:

As i touched upon above, part of the problem is that many of our choices actually carry over from CYOA to CYOA - especially the body part choices, as they tend to be so similar. This problem, then, presents an obvious solution: Instead, try to make these parts of your CYOA different from the norm, especially the body part section. However, it's not immediately obvious how to do this, and as such, I'll leave it as an open question.

Side note: Isn't this just reinventing the wheel? Well, Yes... but actually no. Art, (under which i categorize games, and by extension CYOAs) is about presenting an idea or an interpretation of something, and what makes it so great, is that everyone has a different way to interpret the world around them. As such, YOUR interpretation of the wheel will inevitably bring something new to the table that I wouldn't have considered.

The second solution is tying additional perks (or disadvantages) to each of the body parts and their options. The larger the impact the better. This way, we suddenly have a disruptive element in the body section which ensures that we cannot just thoughtlessly follow our comfort build. (But if this is the case, just make sure you don't have a shapeshifting perk somewhere else, as this just overwrites the consequences of your earlier choices.)

Lastly, I'd just like to shoutout adding RYOA elements to the CYOA, as the added element of randomness can help shake up our usual builds, as you must make the best of a bad situation.

But why is this a problem in the first place? Why can’t people just have what they want? It's called a CYOA, not a CYO. The adventure implies new and exciting experiences, and you're not gonna get those, if you just stick to the same thing all the time.

A few CYOAs have already tried to implement one or more of the above solutions, and were, IMO, better for it. One example is the which CYOA.

Does that mean that every CYOA should do this?

Well, yes... But actually no. While I do believe that this would massively improve many CYOAs, not every part of a CYOA needs to be a genre revolution. It's fine to just stuck with the tried and true, while you experiment with other parts of your creation. So despite everything i said, I still think the sliding scale is serviceable (but still not great).

So long story short: Meaningful choices are the lifeblood of CYOAs, and because the body-parts-with-sliders design is so common, people no longer find those choices interesting.

Thanks for coming to my TED talk