My understanding is that the way mortgages are amortized you're mostly paying interest early on so it takes time to accrue equity but yes if your ultimate goal is to acquire rental properties then it could work out though it requires taking on quite some debt since you taking a home equity loan before paying off the initial mortgage. Depending on your circumstance you might not even need to get a 2nd property though, part of the reason I advocate for the right to build ADUs and renovate single family homes(SFH) into multifamily ones(MFH) is to facilitate what they call "house hacking" where you rent out some part of your primary residence. If you bought a home, built an ADU, and then rented out either unit to help cover the mortgage while living in the other that's a smarter investment than merely buying the SFH and hoping it appreciate.