Sure. But desireable from a standpoint of what makes the organism more like to survive. Not by male fantasies.

There are also limits to extremes. For example, giraffes would be better off if their necks were longer. Clearly, there's been an evolutionary push toward long necks in giraffes but why aren't they getting longer over time? The fossil record shows they've stalled out.

The answer has to do with physical limits from other factors having to do with blood flow, heart size, and environmental conditions not being what they need to be to support a population of much larger giraffes.

Seriously. Read The Descent of Woman by Elaine Morgan.

Breasts in human females have a lot more to do with babies and how our bodies hold remnants more suited to water living than land.

All of the other furless mammals live in or near (and utilize) water. That's your evolutionary push. Not male fantasies about attractiveness that change every generation from the influence of marketing propaganda.

Also, breast size, shape, and firmness is not static. Are you suggesting men are too stupid to realize this despite having eyes to see multiple women ovee multiple yearsbof their lives? Sort of makes it an idiotic criteria to select mates from, don't you think. Men are attracted to primary colors too, yet women have not evolved to be bright red, blue, or yellow.

Finally. Human females are not the only mammals with permanent breasts, at least not in the way you usually see discussed online. First off, they're not really permanent. You're not born with them. They don't develop until puberty. In the literature, you'll find mention of a few animals, like elephants who maintain more permanent breasts after having their first young. What doesn't get said outright is that most animals mate at the onset of their first puberty. So maybe it's not the giving birth that precipitates breast development in elephants but rather puberty, like humans. Humans are the anomaly in that puberty has been arriving earlier and mating age has increased along with the increased timeframe of childhood. That's not being taken into account when describing "permanence" of breasts. Neither is the availability of dietary surplus available to humans because we store food and wear proteftive clothing in order to maintain the protective fat around mammary tissue. Were those things not a part of how we live, it's unlikely and unreasonable to addume that breasts would remain as static as they do in human females.

My dog is an intact female with a solid, presictable diet. She has "permanent" breasts. They're not pendulous, but they're also not engorged with milk or enlarged preparing to produce milk because she's never been pregnant. But they're there, they're discernable, and there's a small protective fat layer around the mammary tissue.