More Highly Valued Companies Stay Private - Smaller Retail Investors Can't Connect

Per WSJ article - "More Big Venture-Backed Companies Shun IPOs, For Now"

"For stock-market investors, the trend signals they are getting fewer chances to buy into promising companies early on. “The loser in this case is the individual retail investor,” said Scott Kupor, managing partner at venture firm Andreessen Horowitz of Menlo Park, Calif. “More and more of the appreciations of these companies will happen in private markets. If you…can get access [to these deals] you’ll get the lion’s share of the growth."

Any of you really smart people have idea's to correct this issue and further democratize investing?

Also, what does the S&P500 even represent anymore? Is this really an accurate bellwether when it excludes a lot of highly valued, innovative (private) companies? If so, it seems like it may be understating the strength of the US economy.