SP500 has been an universal accepted default investment tool for long term. Every company's 401K will have some kind of SP500 index fund available. Buffet said you would pay a high price for a consensus. Naturally, for such a popular investment tool like SP500, you would pay a premium for it. Just watch the price jump when a company is announced to be added to SP500, so many index funds have to buy in blindly in a short time. A built in premium is very obvious which I do not like.
Second, SP500 are made up of mega companys like citigroup, I prefer small companys before they are added to SP500 or bought out by SP500 companys. Small beats giant when you are talking about long term, 30 years ago, walmart, HD, google, microsoft, intel ... they are not in sp500.
Third, sp500 is a good investment tool for lazy people, but many people on this forum interested in investment, SP500 is a waste of talent. If you invest in SP500, why bother study investing.