I think the parent took the literal answer of “no” to be a bit terse, depends on how you read that example conversation. I doubt anyone is arguing it’s actually rude to refuse to provide a phone number, just to not be snarky when doing so.
If it’s uncomfortable to ask then don’t take my response personally. I don’t do it to be rude, just found this to be the most effective way of making a statement without saying much more - which is more likely to make the cashier upset given my resting tone.
Radio Shack used to always want a bunch of information from you for their database, whenever you would buy anything, cash or not. It was good training in refusing to participate in data harvesting that, 30 years after my first nervous "No", is more relevant and necessary than ever.
I'm not saying you should say yes to be agreeable. Just be polite but firm. I would say something along the lines of "I don't want to give out my phone number sorry." or even just shaking your head back and forth works.
"Do you have a phone number" "No" comes off as you being irritated and will make the staff member feel like a dick for just doing their job.
I'm not saying you must always be polite. If somebody is being a pushy asshole push back. However if you can take a few seconds to make a minimum wage drone not feel as bad about their job its well worth it.
At 5'11", I fluctuate between 115 and 120 lbs and cannot comfortably sleep or sit on any hard surface. It feels like my bones are touching stone directly, and sometimes causes parts of my body to fall asleep. It also doesn't help that I sleep on my side.
Fairly certain I'm an outlier as well, but a soft mattress seems to give my body the contour and padding I lack naturally.
