if we define easy vs difficulty level as how hard it would be for the averaged untrained person to get in on the game & start/ continue making money off it (ie. not talking about how easy vs. hard Buffett finds it to make good deals),
there's probably an inverse correlation between difficulty/ expertise level required & amount of lifetime profits/ ceiling vs. floor in the strategy
it's like, anyone can walk in & go gold prospecting in those tourist locations in California, and marginally make a few bucks on average, but the opportunity cost is probably not worth it
vs. the difference of,
- a career/ expert geologist forming his own company, putting together capital to acquire promising lands & striking a motherlode - i've met a guy who did this and he became superrich in <1-2 years after toiling in obscurity for the first part of his career. sure, he was probably also lucky, but he was the real deal knowledge wise, which is how he made money in the venture instead of getting scammed like many amateur weekend geologists
- the companies trying to mine asteroids - the potential profits if they manage to get it working would be insane, but the barriers to entry and expertise required to get the projects working are also insanely hard