Galvanized pipe will often "fill" with corrosion and debris over time, gradually closing off the pipe and lowering water flow kind of like a clogged artery.

If you take that gradually increasing monthly cashflow, and reinvest it, (lets just say into the stock market), then after 30 years your home is 437k, plus about 426k worth of stocks (10% annualized)  thanks to constantly adding additional capital every month from your cashflow. 

Beginning in 2023, this deduction will be gradually reduced until it is phased out entirely in 2027.

Unless you consider getting out of a deflationary period gradually is inflation.

Well that means I'd make 5,300 a year or so from that and it would gradually go up as the principal built up.  

No way your existing tenants can be gradually increased, their base rent is way too low.  

There will always be NEW development that will attract people but if there is nothing that can't be duplicated by a new development it will gradually be replaced by one.

You bring up very good points and I think a fair notice, and a gradual increase is probably the way to go.

Being better off means that if you suffer a large unexpected expense, serious illness, temporary loss of job, major home repair, you can charge it to a credit card and siphon money from your investments over the next year to pay down the credit card gradually instead of being left in a financial desert where you know you will never be able to pay more than the monthly minimum on those cards for the next 20 years, while the principal grows and grows until you'r eventually forced to file bankruptcy.Being better off means, if a catastrophic potentially life-ruining event occurs, you can sell one property or take a large piece of your investment money, handle the otherwise catastrophic potentially life-ruining event, and still have more net worth than 93% of all Americans.All of that reduces latent stress on the brain. 

When the tenant’s lease/TAW agreement is up, do a gradual increase and write a letter about increasing the rents and attach a Rentometer/MLS report of comparable units in your area and how much those are renting for at market value vs what they are currently paying, and that you do not want to just move them up to that market amount right now, but you appreciate them as a tenant (only if applicable lol!)