This is a use case that might no resonate with you if you are from a developed country with a “stable” currency and a bearable inflation rate.
This exactly. Bitcoin fluctuating by 10-20% might not be ideal for a currency at the moment (but we've already discussed how the volatility will improve with adoption over time), but it's sure as hell better than fiat if your fiat purchasing power is halving every month.
Any type of conversion prior to "directly" paying a bill or purchasing a service with BTCitcoin, defeats the purpose of using it as a currency.
It also causes all the issues regarding volatility. Everyone is working from the presumption that fiat is still "the" currency, everything is priced in fiat, you use fiat to buy bitcoin, you sell bitcoin to get back to fiat so you can spend fiat on goods and services, etc. Ideally, you would want to get to stage where things are priced in bitcoin. If I earn a salary of 0.5 BTC per month, and my rent is 0.05 BTC per month, then it doesn't matter if that 0.5 BTC is worth $1,000, $10,000 or $100,000 - I always know that I will have plenty to pay my rent.
Perhaps we should start talking about how much a dollar is worth in bitcoin, rather than how much a bitcoin is worth in dollars. Currently $1 is 3000 sats. Perhaps we should start using graphs like this one -
https://usdsat.com/ - which instead of showing the volatile price of bitcoin, show the ever declining value of fiat. Note that the scale on the bottom graph is logarithmic.