Bitcoin isn't inherently correlated to stocks, but human psychology and investment flows make it look correlated. The liquidity pool and investor psychology are what causes this, and it's NOT the result of investors being "naive." -- It's the result of how the markets have always worked.

Bitcoin does not sit in a vacuum -- it's a part of the global economic system. It is very rational for BTC to follow major stock markets like those in the U.S., which is the largest economy. People invest in all kinds of things for one exact reason "wealth expansion". If they feel that their stock, commodity, coin, or whatever isn't going to be receiving money from other investments, they will take their money and put it elsewhere, where they expect the rest of the money will go.

Most people treat Bitcoin and crypto in general as a high-risk, high-reward investment. So when the general market sentiment is bad, the crypto market is the first to receive the hit, given that it has a relatively small market cap and is subject to huge drops.

Eventually, when people start treating BTC as a reserve currency or safe haven like gold, the correlation between it and other markets will start to invert -- when markets are risky, people would buy BTC, and the opposite is true. BTC has not grown this large because of its usability -- it is what it is now because people believe that it has the potential to grow their wealth, and it will continue to be treated as such for decades.