Obviously there are about 1,000 different things needed to make such a decision. Look at the properties in your price range, the expected maintenance, what kind of renters you expect to have, what the market price is for a similar rental, whether you will hire a professional landlord or DIY, etc...
Compare the expected ROI to what you think you could get long term from just an index fund(~7% to 10%).
And, of course, others have pointed out that a good rental property can provide a little more income security during a bear market, allowing you to FIRE with less total NW.
So find a list of good rental properties and run the numbers. You cannot go wrong either way as long as you do your research.