Unwarranted rent rises

Picture this. Landlord owns over 100 units. Has done so for more than 50 years.
Easily bringing in over one million 800 thousand dollars a year.
Over 50 years, how much would have been accumulated?
Notice of rent rise each year. This time $100 a week.
Anyone out there tell me how the constant rent rises can be justified?
Remember, currently bringing in $1.8 million a year.