You make an interesting point about the temporal inefficiency caused by the time spent dealing with hidden fees and tips

"Second, it's not clear that the time saved would necessarily be redirected towards more productive activities. After all, people spend their free time in various ways, not all of which contribute to economic productivity. They might just as well spend the extra few minutes per day watching TV, for example."

I personally would rather condemn 1,706 newborns per year to a lifetime of watching TV than a lifetime of calculating tips and re-considering purchases solely on the grounds that it would be a significant improvement in enjoyability and intellectual stimulation. One can only calculate 18% so many times before reaching a point of diminishing returns in that regard. Also, in reality, a few extra minutes of watching TV per day does appreciably contribute to the economy. They are consuming a product, television, and they are being advertised to. Their viewership increases revenue for the television network and provides value for the advertisers.

"Lastly, while it's true that studies have shown that hidden fees can turn customers off, it's also true that businesses often use these fees as a strategy to advertise lower upfront prices and thus attract more customers. I wonder if banning such charges might lead to fewer sales for some businesses, which could potentially offset any gains from increased customer satisfaction."

Yes, and banning theft reduces the revenue of thieves. Banning unethical business practices ought to be done because the ethics of a business practice are measured by their impact on human happiness, and the only goal of an economy should be to maximize the enjoyment of life. Who cares about random numbers going up? That's a very autistic way of looking at the economy, and if random numbers going up is the objective then inflationary spending would be the most effective way of getting there, not nuanced economic policy. Money is a tool to facilitate an efficient system for improving quality of life. That's all it is. It's not a goal in and of itself. Macroeconomic decisions can only be made by calculating their impact on quality of life.

"On the topic of tipping, I agree that it can create uncertainty and potential hardship for workers. However, removing tipping entirely might not necessarily lead to better outcomes. For example, it might lead to a decrease in service quality, as workers no longer have the incentive to provide exceptional service in hope of receiving a larger tip."

Excellent service is a baseline expectation. For me, excellent service is simply performing the job duties. Listen to my order, bring it back in a timely fashion, and don't be surly with me. You know what motivates that behavior just as well as tips? The threat of getting fired, which every single employee, including service employees, faces on a daily basis. Again, I have never had a problem acquiring exceptional service in Europe, where tipping is not expected regardless of service.