Bank pays taxes on their income. That interest rate IS their income. Yes double taxing would be bad.

But thanks for proving my point! You cannot deduct your mortgage. You can only deduct specific aspects of it. All of which is not the actual mortgage principal itself. So when you buy a $500k house... even putting 20% down and end up paying $506k in interest over the loans lifetime... Yeah, you're not paying interest on another companies income. That's pretty standard. You're still going to be paying taxes on the 500k principal balance of your mortgage, and property taxes on top of that!

while rent is constantly going up.

Yes because materials to effect repairs on your house/apartment are also going up. Skilled labor costs for effecting those repairs are also going up. Property taxes are going up. Costs to insure properties are going up. HOA costs are going up (If you live in one). Mortgages are NOT the only thing that your landlord has to think about. Nor the only thing that they need in order to break even on the property itself. But you wouldn't know since you apparently have never owned one before. Lots of people are being priced out of their own OWNED homes due to the above factors. Hell I had to replace the roofing on my patio... A 10x30 square fucking roof. Cost me nearly $6k. That shit would have been like $2-3k a few years ago. If I were to rent that house, I'd need to add $100/mo in order to account for that cost over the next 20 months... Where inevitably something else will break and I'd have to find money for that too. If you want to be pissed that your rent is rising, be pissed at the people currently fucking up the economy and making everything fucking harder. That's why rent is rising. It's a pressure on EVERYONE renting properties out to raise so they can all do it safely without worrying about market competition.

Edit: Also... Live in an upscale area where price of housing is high anyway? You may not be able to deduct the full interest costs either!

However, there are mortgage deductions limits to be aware of:
Loans taken out after December 15, 2017 – limit of $750,000 ($375,000 for married couples filing separately)
Loans taken out on or before December 15, 2017 – $1 million ($500,000 for married couples filing separately)

Edit2: oops. wrong word.

Ah yes, the actual mortgage value... the principal is definitely covered in the deduction of the interest... The interest definitely isn't literal income for the bank and they definitely don't pay taxes on income that they make.

Edit: Also there's caps on that value anyway...

However, there are mortgage deductions limits to be aware of: Loans taken out after December 15, 2017 – limit of $750,000 ($375,000 for married couples filing separately) Loans taken out on or before December 15, 2017 – $1 million ($500,000 for married couples filing separately)

With the prices of homes now... It's entirely possible you're completely fucked and paying on that interest anyway.