Japans stock market has taken 20 years to recover. Supposedly it was trading on 80 times earnings. The Japanese thought they would never have another recession. When the banks leant money to companies they bought shares in them which became part of their reserve ratio. When the market started to fall they bought more shares in them…without telling the market. The rest is obvious. Even today Japanese accounts can sometimes be fraudulent.
UK is cheap relative to other developed nations and its difficult to get away with fraud. For the market to continue down much further say 20% then dividends would be to tempting not to get people buying.
Of course it is possible for the economy and the stock market to go into free fall. A nuclear war being the obvious. If so then i dont think i would give a shite about money.