Many(most?) GA pilots use noise cancelling headphones for a reason.
Road vehicles have silencing weight budgets way beyond what is feasible on an aircraft.
Electric cars are still noticeably quiter anyway.
YO-3 went to great lengths to contain engine noise, far beyond a special muffler.
And reducing noise is just one (and not the most significant) benefit of an electric propulsion.
I am not saying it does not have serious practical drawbacks ... but you have to look at the whole picture, and there are benefits that do not show if you look just at price/weight/performance numbers.
It's not hard to reduce the exhaust noise of an aero engine to well below prop noise. it's rarely done as it is rarely required. An unnecessary muffler is unnecessary weight and cost. A muffled aero engine is still going to weigh far less than an electric system of any duration.
Here's an Edgely Optica, notice how quiet it is compared to other aircraft taxiing nearby. It had a ducted fan for reduced noise compared to a prop.
Can only barely hear the engine on the Optica. Sounds like a big electric vacuum cleaner.
I have tested electric R/C airplanes with my sound meter that were louder than a well muffled gas model.
Pusher noise can be really annoying. Especially the Avanti. The Avanti flew over me and I could here it for several minutes, all prop noise.
Prop noise video:https://m.youtube.com/watch?v=Dk4jNSBwl4Q