Fannie/Freddie both offer investment property loans with 20% down/equity IF YOU CAN QUALIFY.
Pricing is better with 25% and slightly better with 40% down/equity. Applies to purchase OR refi.

Today, 5.00% was possible with no points and 25% equity on a 30 year fixed. Loans up to $417,000.

Loan limits/rates are higher on 2 to 4 unit properties.

It gets complicated if you do not have a 2 year history of being a landlord with other properties.
You may have to qualify for the entire payment + taxes, insurance and HOA, without any credit for potential rental income.

On a refi, they look at schedule E of tax returns and add back depreciation to the bottom line to figure the net income/loss.
I don’t think that 75% is used anymore by anyone.
That was several years ago.

You generally need at least 6 months liquid reserves for rental properties. Retirement accounts like PERS that cannot be borrowed against may no longer be used for reserves.

There are way too many restrictions/variables to list. Many people will not qualify without substantial income that will be accepted. Straight salary is easy to verify. Bonus, commission or self employed income can get really complicated.

There is no such thing as an easy loan today.
Even 50% down and loads of cash in the bank and a high credit score doesn’t make it much easier.
There is no one simple mortgage rate that everyone can qualify for.

Rates are close to historic lows but the lowest % of the population in history can qualify for ANY loan today, purchase OR refi, primary or investment.
It is more even difficult to get a loan on condo rentals.

For the lowest rates, banks don’t make up their own rules. F/F make the rules and banks are just mortgage brokers, many do not offer the best rates or programs as they have additional guidelines.

Websites that show rates will not show what you actually qualify for, and if they don’t know your credit score they are probably only quoting for scores above 740.