Last house I rented, when I moved in the dryer lint trap and its housing were so jammed full of lint I could have made a blanket from it. It was astonishing. I don't think the prior tenants knew it needed to be cleaned ever. I honestly wonder how the dryer wasn't broken and no fire had started.
The HVAC filter had a solid inch thick cake of dust and dog fur.
I've been living in apartments for the past 18 years and this is the first place I've had that the washer drier has a dampness sensor. It took me about 4-5 loads to discover why it would say that there was an hour left and then turn off like 35 minutes later with some stuff still being damp.