I rarely traded financial instruments so cannot say for that, but as a small landlord I wish I never entered the business. Like, all businesses need initial investment AND a lot of continuous effort and learning, and are probably boring (or VERY barricaded) because otherwise people are going to swarm in. I need to know the market, the laws and regulations, and some other stuffs, most of which are extremely boring and not really "hackable" (as for hackers) because accountants and governments already sorted everything up to make sure it's hard for small businesses to evade tax -- You can learn which parts are expenses in an afternoon, and then you have to deal with a lot of headaches.
I know some people who own gas stations and large depanneurs (in QC they are independent convenient shops), which are luxurious on face, but they either have to pick a remote one (away from competition from supermarkets) or/and work 7 days without hiring an extra hand. They grind for 10 years and sell the business when time is good.