Not all wall street firms end up success, many were bankrupt, but you won't hear the bankrupt story. The higher the leverage, the higher the bankruptcy risk. And for sure, real estate business has the highest leverage across industries IIRC. What I want to say is, you don't always need leverage. You can be wealthy from side hustle without borrowing any money. The key is reinvesting your excess income, not from debt.
Same way not all who choose a career end up with them. The fact the process didn't work out for A doesn't mean it wouldn't work out for B. It's more riskier not to take the risk. Most successful investors failed during their early beginning and went bankrupt but their determination and passion kept them burning and today the process pays so if leverage is the only option use it but be wise with it