Are the cannabis stock's best days behind it?Before Canada legalized marijuana in 2018, Canopy Growth (CGC -3.79%) was seen as a top cannabis stock, an industry leader, and arguably one of the best stocks to invest in for people who were bullish on the prospects for marijuana reform at the time.Fast-forward to today, and I would hesitate to classify the stock as a leading company or a top growth stock to own. There are larger cannabis companies than Canopy Growth out there, and it hasn't been much of a grow ...