This is truly just my personal opinion, YMMV, IANAL, talk to your doctor, etc. But personally I find putting a hard requirement on needing 20% down to buy a house to be a bit extreme in these valuations and this market for a first time homebuyer. I was entering the market wanting to do that, my partner ended up finding a house that I just couldn't say no to. My partner and I ended up buying a house even though we only had a bit over 10% down about a year and a half ago. If we had waited another year of saving up for a down payment, we wouldn't be able to afford the neighborhood we live in now. We paid 1 year of PMI (<$1,000). We refinanced at a lower rate and no longer have PMI as the valuation increased so much that we already hit >30% equity in the home. The P&I, insurance, and taxes after refinancing are
less than the rent we were paying for an apartment down the street with less than half the square footage, no garage, no private yard, no EV charging, etc. And rent there has gone up, not down.
Don't get me wrong I'm not saying the 3% or less you can technically get away with are a good idea. I'm just saying, in this market having a hard rule of 20% down doesn't make a lot of sense to me. Do the math on your finances and what seems to make sense in your area. I'm certain the market is different where you are from where I am, there's a lot of nuance.