This strategy makes sense, but it carries with it the risk that you will not be able to sell at the absolute peak - or that exactly what you want will not happen in the time you have imagined. Of course, if you sold 1 BTC for $100k and then a correction happens that knocks the price down to say $30k, you could buy 3 BTC and you still have $10k left to spend on something else. All of this is only possible if Bitcoin continues to replicate a pattern from the past.
And I think there will come a time when it will no longer be necessary to convert BTC to fiat, not only for price stability, but also for the reason that Bitcoin will become a means of payment in almost all situations - and maybe sellers will gladly accept it and give extra discounts to those who choose this method of payment - because Bitcoin could become something very valuable and difficult to obtain in some 10 years from today.
If you look at the example above, then a partial exit strategy is not a bad choice - whoever sold 1 BTC for $20k at the end of 2017 could buy 6 BTC for the same amount in less than 1 year - and a couple of years later that same BTC was worth about $400k. All those who have learned something over the years have profited, in other words they have more BTC than they had before, and at the same time their standard of living has improved significantly thanks to Bitcoin.