But I have failed to see any such mining setup and investments in the same till date that are legit and have not been scams.
If you are talking about cloud mining, then there are many difficulties in this business. The average miner has very few opportunities to buy cheap ASICs and get a good price for electricity, so most new small miners will now find it very difficult to compete with large mining companies.
Buying bitcoins or shares of mining companies is an individual choice. The stock market is more regulated by law, and many investors find it easier to buy shares while there is no Bitcoin ETF.