Depending on the season, if the market is already on dip, you may choose to invest and hold till we are out of it, to DCA comes with a clkind of double advantage for those interested in using it, the first aspect is the way it helps in buying gradually as the income flow in for us, then we take advantage of investing without missing out in the buying opportunity over time and we are buying at every dip.
Secondly, it helps reduce the risk of losing more at the bear market where everything seems to be hard to make profits, our own loss will be minimized and we can easily com out of it because of this strategy serving as the best alternative approach for long time investors, because they can hold and over time make profits the more with their assets as the market rise, her have to understand the reason for anything we choose to take, while at the verge of investing in bitcoin this season.
There is no need for a market crash to invest, there is no need to depend on market seasons, etc. There is nothing to depend on. If you have a source of discretionary income, basic knowledge about Bitcoin, and faith in Bitcoin. If you have these things, it is never a good idea to wait to invest. You need to start investing as soon as possible. Buying during a recession is always a sign of a business. An investor will want to continue buying until he can accumulate enough Bitcoin in his portfolio. If someone has money to invest, then he can invest it immediately. Waiting for a crash is not a good idea at all, invest as soon as you have money.
A bear market never helps reduce risk. A bear market becomes even more risky, for example. Suppose the market price of Bitcoin is $10, you buy it today for $5 after the market falls. But if the price of Bitcoin drops even further after you invest, you will be even more worried. Bitcoin is a very volatile currency market, and you never know when it will happen. A bear market never reduces risk.
I agree with your core point that waiting for a "perfect entry" is usually counterproductive, because the market rarely moves in the way people expect. If someone has discretionary income and long-term conviction then starting as soon as you can is much better than waiting endlessly for a "perfect entry"
However I think its worth clarifying that bear markets are not entirely useless for investors. They do not reduce the risk or volatility as you said correctly but they reduce the entry cost. Historically, anyone who bought BTC in 2015, 2018 and 2022 had significantly lower average buy price than those who bought it in the peak of bull run.
The most reliable approach is DCA in every phase of the cycle whether bullish or bearish. While no one can predict exactly when's the exact "best time" to invest but historically a bear season is an excellent opportunity and we should try to accumulate more if we have spare funds because Bitcoin has proven to be bullish in the long term.