This is a topic that used to be a frequent topic of discussion on this forum. There are a lot of opinions on this topic but there is no one universally right answer here. My take on this is that tillers have more feel and less friction than a wheel. They are more direct and so allow a quicker response and a more linear response. Because of that it is easier to get higher performance out of a tiller on a smaller boat (say under 40 feet or so). I consider most wheel steering installations so slow responding and so restrictive of movement around the cockpit that they are dangerous on boats under about 30 feet ans see them as an affectation one rather than an asset on boats this size.
Tillers generally have less mechanical advantage than a wheel and so on a boat with large helm loads; a tiller will require more strength to steer. On a modern fin keel/ spade rudder boat, the steering loads tend to be lighter and so the mechanical advantage of a wheel generally is not as necessary. In the case of a boat with high helm loads, a tiller is more tiring. In the case of a boat that is well balanced, a wheel (because you not only have to move the rudder but also overcome friction) is more tiring.
I personally like a tiller. I find that by using a tiller extension it is easier to move around and see the trim of the sails, find a comfortable position to sit or adjust course. I find it tiring to have to hold my arm out to reach the wheel rather than to just sit with the tiller extension sitting on my knee. I do a lot of single-handing and strongly prefer the ability to have a tiller extension within my reach almost anywhere in my cockpit.
I find that it easier to use shock cord to pretension the tiller to hold a course than it is lock off a wheel which can only hold a fixed position rather than flex as the loads increase allowing the boat to “find its own balance”.
Tillers work well on modern boats up to about 40 feet. Wheels work better on larger boats and heavier boats because the loads are greater. Autopilots used to better for wheel steered boats but now can be purchased in equal quality for both wheel and tiller steering. Wheels involve a mechanical system, which in my book is just one more thing to maintain and to break. I hate crawling under the cockpit by way of a cramped sail locker, hanging upside down to rerun a steering cable that has jumped the quadrant. That seems to happen less with more modern wheel steering systems but it still happens.
Tillers seem to be more preferable for coastal cruising while offshore cruisers seem to prefer wheels. Mass production boats seem to show up with wheels these days. Specialized boats seem to show up with tillers.
Tillers swing through a bigger area of the cockpit but wheels permanently occupy a bigger area of the cockpit and are a pain in the butt to get around. Tiller can be tilted out of the way when you get to port; the binnacle for a wheel can support tables and the like. Binnacles give you something to hold onto in a seaway.
Some people feel that wheels are more nautical or shippy. Others think that wheels on small boats are an affectation like the small boat sailor who wears a captain’s hat.
In the end, it comes down to what you feel most comfortable with. Each has their proponents and advantages.