We often say in economics that there is no free lunch. I don't know how much it would cost to be lovely, but if the price rose for some reason, then people might not try as hard to be lovely. So the cost or price should be a factor in this. Or, if the price of other things fell, then people might not try as hard to be lovely.
We also say that people want to maximize utility. And wanting to be lovely might just be one item or argument in a person's utility function. How does a person maximize utility (if they spend all of their income)? They buy a quantity of good A and a quantity of good B to make this equation true:
MUA/PA = MUB/PB
MU is marginal utility or how much satisfaction you got from the last unit consumed of a good.
Suppose a person wants to be lovely (good A) and play video games (good B). If the price of B falls, and nothing else changes, then
MUA/PA < MUB/PB
which means that the person is getting more satisfaction (or utils, a unit of satisfaction) from good B than good A. So they will want to consume more of B. But then they have to spend less on good A (maybe it terms of time or resources devoted to it). And you get a person who tries less to be lovely than they used to.
See Adam Smith and Loveliness from Liberty Fund, Inc. Here is the full quote from The Theory of Moral Sentiments and on the Origins of Languages (Stewart ed.):
"Man naturally desires, not only to be loved, but to be lovely; or to be that thing which is the natural and proper object of love. He naturally dreads, not only to be hated, but to be hateful; or to be that thing which is the natural and proper object of hatred. He desires, not only praise, but praiseworthiness; or to be that thing which, though it should be praised by nobody, is, however, the natural and proper object of praise. He dreads, not only blame, but blame-worthiness; or to be that thing which, though it should be blamed by nobody, is, however, the natural and proper object of blame."
This reminds me of a discussion of Maslow's hierarchy of needs in the book The Best of the New World of Economics...and Then Some by Richard B. McKenzie & Gordon Tullock. They said that which need a person satisfies might depend on the cost of achieving that need and that people might not necessarily do them in the order that Maslow suggests. If the third highest need is cheaper to satisfy than the fourth highest, then a person might skip the fourth highest.
So the same thing could happen with Adam Smith and loveliness. It might be something a person desires, but if getting there is too expensive (or if the price of something else falls like it gets very cheap to just play video games) a person will engage in fewer loveliness seeking activities.
One other factor that affects cost here might be ability. For some people it might be easier to achieve loveliness. They just might have natural abilities that make it easier for them to do so. Then it is less costly for them to become lovely so they achieve or consume more units of loveliness than others.
Here is an excerpt from Wikipedia on Maslow:
"According to Maslow’s original formulation, there are five sets of basic needs: physiological, safety, love, esteem and self-actualization. These needs are related to each other in a hierarchy of prepotency (or strength) beginning with the physiological needs that are the most prepotent of all. If the physiological needs are fulfilled, a new set of safety needs emerges. If both the physiological and safety needs are fairly well gratified, the prepotent (‘higher’) need of love (both its giving and receiving) then emerges. The next need is esteem, and finally self-actualization. Maslow also coined the term "metamotivation" to describe the motivation of people who go beyond the scope of basic needs and strive for constant betterment."
This Pepper…and Salt from The WSJ illustrates how people like to find low cost ways to get things done, including being loved and lovely. They might not want to pay a high cost for that.
