Any talk about retirement must start with how much money per month you expect to SPEND in retirement. Like if you're living on $5k per month now, will that go up because you are going on vacations or down because you're planning on moving to a cheap commune or something.
Once you have a target number, and subtract your age from your life expectancy age, you have a dollar amount to plan for exactly.
Let's say you're 50 and $5k a month is fine for your retirement. If you plan to live to 90, then you need no less than $2.4 million dollars to fully retire on.
Bitcoin is obviously going up, so the only question remains is how little bitcoin can you stack in order to make $2.4 million worth in the future? It may be less than 1 bitcoin in the long run but for the next few years you'll burn thru more than 1 BTC per year at current rates.
Realistically, you're probably going to need something like: 1.5 BTC for 2023. 1 BTC for 2024 1.5 BTC for 2025 0.5 BTC for 2026-2028 0.01 BTC for 2029-2031 0.0001 BTC for 2032 etc Then in 30 years you will probably be about to treat sats like today's dollars. (i.e. 60,000 sats for 2053 onwards)