This means that buying at the time when the price is on the increase is not wisdom
I disagree with you and if I may ask when do you think the price of Bitcoin will increase? Doesn't it mean that if Bitcoin should surge or skyrocket to $500k investing in it will be lack of wisdom?. An investor doesn't care if the price of Bitcoin is increasing or not because the DCA method is there for them to accumulate Bitcoin whether increase or decrease and i want to believe this statement is for people that trade Bitcoin and not for investor because investor doesn't have any problem with Bitcoin increasing rather it is only traders that does because they only focus on entering at the low price and hoping to sell when it appreciate.
This one of the role dca buying plays in bitcoin investment. Which serve with the purpose of purchasing bitcoin being able to purchase bitcoin. Either weekly or monthly could be any of your choice that suit you , most salary earners usually fixed their accumulation plan monthly buying , buying whether the price up or not they just buy because they just want to build their bitcoin stash.