We bought two after moving to Ireland. Both have drainage hoses. One has a pump and empties into the kitchen sink, the other has no pump and the drainage hose empties into the shower. No more mold problems.
Ours has been on constantly for nearly a year. Any decent one has humidity set points - we set ours for 55%. It's a bang-bang controller with a 5% range - it'll run until humidity drops to 52%, then turn off until it rises to 57%. During the winter our single one struggles to get much below 60%, we might add a second next year.
An unexpected benefit (for us, as its not something we're used to) is its virtually "free", as we don't have to run the electric clothes dryer anymore (nearly €4/load). We just hang the clothes on a rack by the dehumidifier and it dries them out in a few hours. My wife is starting to prefer it as its not destroying clothes nearly as quickly.
It’s not free as the dehumidifier has to do more work. If you have a modern heat-pump clothes dryer you might be using more electricity by abusing your humidifier like this.
If you live in a hot/humid location your HVAC is much better at dehumidification than a dehumidifier, since a dehumidifier outputs a ton of heat to operate. But in a cool/humid location, you can definitely rig up one to be decently set and forget. You still need to perform maintenance (cleaning the grill, adding a bit of white vinegar to the water tank to kill growth buildup, etc).
I actually put mine into the HVAC cabinet and used a smart plug and smart thermostat to turn on the dehumidifier and the HVAC fan to dehumidify the house. But that’s way more than you need to do for a small apartment.