You are looking at it the wrong way, Because the market has traded mostly sideways for a while that means that the market is underpriced compared to what it should be. That is when you should be more willing to invest. I know it seems counterintuitive. This article explains the concept better than I can.
Since ~2019, the SP500 has gone up 45%. That is the equivalent of a 8.5% compound interest rate or 11% simple interest rate per year. If you’re portfolio accounts are under performing that by a big margin than you might want to switch Funds and/or account providers.
There are always gloomy articles and headlines meant to convince you to sell. Because they want to buy your stocks on the cheap.