Because share market cannot go up like houses. With houses you...

Because share market cannot go up like houses.
With houses you have ever increasing newly created debt by 10% per year, and not much new supply. So here is your ever increasing bubble
With shares it is mostly cash. Plus many companies burn capital, issue new shares, but people have the same salaries lately. Share price go up only of select companies when capital is moving from somewhere into these shares.
This is a concept. There are details like % and mining booms and bubbles and money moving from bonds into stocks or other way.
Individual shares are even worse. Especially mining. They eventually deplete resource and spend cash on salaries and go to 0. Only several largest survive by swallowing small bankrupted miners. Even BHP didn't move much in the last 10 years. Check long term chart of BHP and AGO. BHP is flat, AGO collapsed.