It can suck. But with renting, that’s just one more layer of rules to navigate.

If the owner you are renting from does allow you to make these improvements, years later they can decide (or sell the property and the new owner decides) that they like what you have done and they won’t be renewing your rent, now you are out and have nothing to show for the work, no value to you for the time and energy spent and you have to start over.