They're making a statement about the unit of account that you choose to use. I know some people who only price some things in sats because thats just what the price is for them. That's the unit of account that they use.

I think it is also often used to highlight bitcoin's absolute scarcity but I don't think it's an accurate comparison. I think a more precise and accurate expression would be "1 bitcoin is 1/21,000,000 bitcoin" because "1 dollar is 1/♾️ dollars"

Just my two sats