The two are not comparable.
This law, S.B. 608, permits a yearly 7% increase on top of inflation. So currently “the yearly limit [is] expected to work out to nine to 12 percent.” That is the max. Actual rents could go up by less than that, if a local economy goes into the dumper. Such as the aluminum smelter in The Dalles going out of business.
Social Security gets an increase = last year’s inflation, and not a cent or basis point more than that.
The rent increase limit allows some flexibility on the upward side to allow for economic differences between places. For example, if Amazon located an HQ3 in Portland rents would go up, until building new housing catches up with the demand. (Presuming that Portland allows new housing to be built…)