SALT and Mortgage only), it is probably about a $300 tax savings opportunity on average. For there to be no benefit, people would need to be paying about $1,200 a month in mortgage interest and be maxed out at $10K on the SALT (clearly you understand but I appreciate the help trying to get other people to understand).

But, mortgage interest goes down over time and the standard deduction increases, so eventually it should turn in most people's favor. At that point hopefully people can prepare in advance to double down...but by then, the tax law may change. :|