This is where Bitcoin knowledge comes to play, it takes an investor that understands that Bitcoin price will always increase and reach ATH in the future. Bitcoin is volatile and no need to wait for it to dip further before buying when you have available fund at hand. Unless you're excessively rich you can spend the fund that is intended for Bitcoin accumulation into a less important thing.
Some people can argue that it is better to buy during dip than when price is pumping, this is true but they need to consider that they can buy at present price then it'll start to rally and they'd be in profit. People who waits till it dip some more before buying will most likely panic and sell if it continues to dip further. If you want to succeed in long term investment you need to care less if price is dumped or is pumping, your goal will be to keep buying into the long term so far you have your discretionary funds at hand.
You clearly made case for long term Bitcoin investment strategy with suggesting that its price will always go up over time due to its limited supply and growing use making new highs. You argue it
is better to buy now with available funds other than waiting for dip as trying to find perfectly time market is tough and due to this we can miss gains or panic selling. This approach is like DCA which helps you buy more when price is low and less when it is high smoothing out your average cost and removing emotion from investing. Ultimately this is disciplined way to invest in Bitcoin focusing on steady buying for future other than trying to predict its short term ups and downs.