Most EVs are in fact liquid cooled. The Leaf which isn’t, has much poorer battery life because of it. EVs do have maintenance items like brake pads and air filters and items like suspension bushings have a finite life. An EV certainly needs fewer regular maintenance activities than an ICE but it’s not zero. And all that is ignoring that some EV manufacturers make you do a regular service to keep your warranty (Hyundai Kia for example)