Mostly when people say lifestyle they mean hours/week, on-call responsibilities, working nights. When pre-meds and sometimes med students talk about lifestyle, they often mean residency or academic medicine. But although residency can be hard (most surgical fields but not all) or cush (psych, physiatry, etc), your lifestyle after you finish training is (mostly) up to you. It depends on where you practice. Theoretically, for most fields, you can choose a practice setting that fits your overall goals. You can choose a surgery practice where you are in a large group and have call less frequently. Or where you only do outpatient surgeries and someone else takes care of your patients inside the hospital.
In most cases, working less means earning less money. Most people have geographic limitations so they don't prioritize lifestyle.
For ENT, certain surgeries are longer and more complicated (cancer, recon?) and patients sicker. You could work at a lower-volume place and refer those complicated cases to someone else. You could focus on clinic, in-office procedures, shorter/simpler surgeries. You can choose to have clinic 4 days/week, and operate 1 day/week, or 1 day every other week, etc. The number of clinic patients you see depends on how much money you want to make.
(This is all mostly assuming you're in private practice and have enough patients in your area who are looking for an ENT that you can decide how many you want to see)