Why are psilocybin mushrooms Class A illegal? (UK)

I don’t quite understand what makes them so dangerous to society, (much the same as cannabis really and other natural drugs). You can pick them out in the British countryside, they grow naturally, you really wouldn’t overdose on them as they taste of feet if you did eat too much you would just throw up and they are not addictive. I really don’t understand why they are a class A drug. I understand its not a good idea to take them if you have mental health problems but surely that is the same as with alcohol and many other medicines too. Please don’t just send me to the Wiki page on the legal status as that just tells you where they are legal. I feel I must be missing something massive here for them to be grouped alongside heroin, crack cocaine and meth…