Howard Marks of Oaktree and various other large institutional investment firms are predicting much lower than average returns from the S&P for the next ten years. Marks offers credit (public and private) as an alternative to the stalwart S&P gains. Thoughts?

Here is the link to the article:

[Howard Marks expects a lower return from the S&P 500 over the next decade. Here’s what he likes better. - MarketWatch](https://www.marketwatch.com/story/howard-marks-expects-a-lower-return-from-the-s-p-500-over-the-next-decade-heres-what-he-likes-better-3d24dc20)

[Public.com](http://Public.com) offers a %6.95 yield on corporate bonds. Is this what Howard is referring to when he posits that credit will outperform for the next extended cycle?

Investing from 1999, when P/E ratios were this high for the S&P, it would have taken 14 years in the market to get to an average return of about %6 per year. Public is offering about that right now. If Howard is correct, what would cause such compressed gains? The concentration of tech stocks, which are highly valued and will have a hard time of increasing earnings proportionate to price over the longer term? Or a correction, crash, recession and long recovery time from such an event? Or both?