One massive apartment complex here in El Paso was sued by the Feds recently because they refused to honor a clause for military personnel regarding early release from a lease due to military orders. This is a huge problem for military families waiting for quarters on post too.
The rental increases also target college communities as well. It may all seem insignificant to a person with secure living circumstances but there are moments of panic when your rent goes up $85 a month in two consecutive years. The stories are heartbreaking. Like being self-evicted because you don’t qualify suddenly.
How is it illegal or unethical if rent goes up when you seek to renew the lease which has fully run its course?
Certainly not the federal government’s delegated job to regulate intrastate commerce or things which are not interstate commerce even though they affect it (no delegated power to regulate things which merely affect interstate commerce).
Unless there is, as you point out, a clause in the lease that is not being honored the renter is at the mercy of circumstances.
As one local fellow who has been pushing home ownership over renting has been saying in commercials for decades now: well bless their hearts.