That strategy is called dollar cost averaging and it works perfectly fine on unpredictable markets like cryptocurrency one. Even if you are an expert, an experienced trader or a technical analysis guru, you can't say with a high degree of certainty that the particular moment in time is the most suitable moment to buy bitcoin. If such experts existed, they would have bought bitcoin when Satoshi was introducing it to a narrow circle of cypherpunks. Since we are not able to foresee the future of bitcoin, the only strategy that is efficient enough is to consistently buy bitcoin at whatever price. However, as many have said, buying bitcoin on a daily basis may cause additional loses due to high transaction fees.