Because cryptomarket is now a part of the traditional financial market and what is happening with the world economy is directly reflected in cryptomarket. You should not think that cryptomarket is something separate and independent. No, it is not, because big money of institutions (traditional market) was poured into this market.
Yes indeed, Bitcoin is being integrated to traditional financial market due to the intitutions taking part to its econom but I do not think it is the reason why Bitcoin fluctuates. And I think Bitcoin still has its independent market fluctuation, and the thought that it is directly affected by what is happening in the world economy is just conincidence and people trying to connect the dot often gives hypothesis or theory that they invented.
The truth is, Bitcoin declining 3% is just the normal fluctuation of its market. As Pooya87
stated, looking at the pattern of Bitcoin price movement, this Bitcoin price changes are just normal occurrence in the market and has nothing to do with the news of inflation rate.