Not everyone can afford to buy 1 bitcoin nowadays, but there are many people who can afford it and it all depends on the budget that each investor has. Buying with DCA is good, even if you can afford to buy 1 bitcoin at a time. DCA will hopefully get them a lower average price than buy with lump sum, so don't ignore that buying strategy even if you can afford to buy all at once.
You may be right, prices are still difficult to predict even before the halving. An increase is certainly expected, but in this situation panic may occur more easily because there are many new investors who do not yet have good psychology about the market. You must be aware that not everyone is able to control themselves when market volatility becomes high, so the potential for correction cannot be ignored at all.
Yes it all depends on the amount of fund a person has and everyone is financially different so some will buy 1 bitcoin and other will buy little by little so financial status matters a lot. DCA method is a fascinating technique that is adopted by many investors of bitcoin hence their profit is huge as they take part in investment with different prices.
There are many individuals who will buy bitcoin now but I think its not a good time to buy because price is already very higher and very few will afford to buy at 69k$ otherwise it needs large portion of money to be used. Bitcoin has a potential to grow but everyone does not think in similar way so many newbies who have little knowledge and they cannot control their emotions will surely sell their bitcoin after a very first pump during halving so they can effect bitcoins price therefore think before you take step.