Everyone knows that there are satoshis in a wallet and not USD. However, that does not mean that people don't calculate in USD.

Those amounts are not useless. You need to connect them to the real world, which for most people means converting them to their local currency and assessing how much they feel comfortable holding in a custodial wallet. This is similar to what they feel comfortable holding in their physical wallet as cash. The amount of satoshis people will keep in a certain setup will change over time (custodial LN, self-custody LN, single sig on-chain, multi-sig on-chain, etc.).