When I worked in mortgages in a previous career, we had a presenter talk to us about Private Mortgage Insurance (PMI). Back in the day, banks by default would just tack it on as an extra insurance for them in case you were to default. You're basically paying insurance against yourself to cover the banks losses. Once it was added, it was basically permanent for the life of the loan.
Then one day, a senator I think from Utah was asking about his his costs after signing. The bank explained to him that it was PMI and he couldn't remove it.
Thanks to that situation, PMI cannot be enforced if the loan to value ratio is below a specified threshold and the banks cannot force it on you if you meet that threshold prior to closing or after you reach it.
In a nutshell, this is what needs to happen before a lawmaker bothers.