Rent control exists in many cities in California, and was designed to keep rent prices low so that more tenants can afford to rent there. And it does keep prices low — as long as no one is looking to rent there. The problem is that rent control is only in effect during the tenant’s residency; as soon as the tenant leaves, the landlord can increase the price to reflect current market values. This means that even if a new prospective renter is looking in a rent controlled neighborhood, they’re still looking at current market rates.
There’s also another reason it doesn’t help renters much, and may actually harm them. And it’s merely the fact that landlords are aware of the above aspect of rent control and readily use it to their advantage. While rent control laws often do also include some form of eviction protection, they don’t outright prevent evictions, and in many cases renters aren’t able to afford to sue their landlords if they were wrongly evicted. This means that in many cases landlords can simply choose to evict their current tenant if they want to increase the rent price, or if they can’t find believable cause to evict, just stop maintaining the property until the tenant doesn’t find the situation livable anymore. Without rent control, prices steadily go up, but landlords don’t resort as frequently to devious methods to raise the price.