warren Buffett has a lot sayings. But one of his statement is like this:" the biggest edge as a retail investor is the "size". If you give me $1million, I can easily achieve 100% or even higher return. but if it is $20million, the return may be dramatically reduced."
For US market, except for those very illiquid stocks, a 6- figure or even low-end 7 figures US dollar market order could be easily absorbed within a second. This is exactly the 'edge' for the retail investor, because a retail participant can get in and out of a stock at whatever price with desired quantity within split second. However, the story is totally different for FUND. A fund has a lot rules and constraints. The set of the rules specify minimum market cap of the stocks they can purchase, minimum holding period, maximum shareholdings, a necessary liquidation (cut loss)requirement, and many others. Therefore, there is a natural tendency that most of the funds have to shift their focus to mid cap or big cap stocks (the fantasy 7 for example) due to liquidity constraint, and obviously most of their FUND performance is just a replication of SP500 or nasdaq100 index.
all great companies evolved from 30m-50m small cap company in the first few years, and those were the fastest growing period in their financials. If one has spare time and money to do stock selection on his own or just simply wants to challenge himself, then why not, just do it. But for many who have a full day job, index fund is still a good choice.