Yeah, if you know when real estate is going to underperform or not. You can increase your stock returns if you time the market and get out when the market’s going to underperform, and get in when the market’s going to outperform - but few ordinary people have the skill to do that (or pick individual stocks successfully, for that matter). The average person isn’t going to be able to know or figure out in advance whether they would do better using their capital as a down payment on a house or in the market.
Over the long term, historically residential home prices have appreciated about 4.3% per year (from the mid-1960’s). The S&P500 has returned about 10.4% per year over the same time period. But because home purchases are typically leveraged, the typical home purchaser’s actual return over a 30-year time frame on a 20% down payment would be about 10.1% - pretty close to the historic return on the market.