It's a mystery to me why so many claim the market is overvalued, etc. SPX forward earnings yield is around 5% while the 30-year is yielding two and a quarter. Compare to 2000 when the figures were 3.5% and 6% (so yes you could get nearly double the yield from risk-free treasuries). That's not remotely a speculative bubble, but pretty much fair value.
Yes, those figures will get blown out of the water if inflation breaks out (forcing the Fed to hike) or if corporate earnings plunge. So if you're bearish, you need to make a clear case for why one or both of those will happen soon.