Still get surprised as a Home Inspector inspecting residential homes for over 20 years at Clayton Home Inspection.
I am without words from time to time for an explanation. Like a dryer vent connecting to a chimney in a basement. Yes, its true I rechecked outside just to make sure my eyes were not deceiving me. I must admit it was creative but, potential a fire hazard. The common problem is that the dryer is located in a first or second floor closet in a tight space. This requires some effort usually requiring moving the dryer from a closet resulting in the dryer vent disconnecting when moving the dryer. Reconnection is a challenge for most homeowners. The dryer exhaust tube is sometimes connected between floors and or just venting below the floor. That is a clear fire hazard.
Dryer vents require connection of a smooth interior metal tube. Connecting too the outside to exhaust excess lint and moisture. I recommend change the water supply hoses to washer to steel braided every 5-7 years. Check and clean the dryer every 6 months. Change the flex medal or plastic to a hard pipe connections with a smooth interior and as short as possible to the outside to allow the lint and moisture to exhaust with little resistance. If you don’t remember when the last time you cleaned the dryer vent or changed the washer hoses, then you probably need to change them.
Call someone who is qualified to clean and replace the connections, do it right the first time. There are many companies now that will do  this type of work unlike just a few years ago. I even had a hard time coming up with a good answer when some ask who would do this type of work. try typing in words like dryer vent cleaning near me.