There is a loophole in AC21: if you have an approved I-140 then you can extend H-1B indefinitely in 3 year increments. The trick is that I-140, once approved for 6 months, cannot become unapproved via a USCIS memo. So there are now hundreds of thousdand H-1Bs with permanent I-140s getting infintie H-1B terms.
How would you buy a house on a H1B? No banks would issue a mortgage to a non-immigrant visa holder.
Two things can be true at the same time. Starting a "resident life" while on a temporary, non-immigrant visa doesn't sound like a great plan; and yes, this visa is horrendous and should be deeply reformed.