Model rail sound systems tend to be listened to at quite close quarters so detailed sound becomes appropriate. Modern systems do perform a lot better than the size leads traditionalists like me to think they should. The better the source, the better the end result can be. A poor start will result in something sounding like a bent spring sctratching over a gear wheel with most of the teeth missing.
On a 00 gauge layout, 64 feet is one mile, a real steam train would be all but inaudible at that distance apart from the whistle, but very few layouts are that size anyway. Many rail fans want to be close enough to see the valve gear working, and that is close enough to hear the small speaker. And they are likely to spot the difference between a small 2 cylinder loco and, say, one of Gresley's 3 cylinder jobbies with a bit of wear induced syncopation. And, of course, they all had different whistles. Thinking of the DMU driver who came past the end of my street a lot of years ago. He played "Ilkley moor baht'at" on his two tone to let his family know he was almost home.
In our world, at 64 feet (about 1/2 mile at 1:32) on open water, you probably want to hear a model boat, but there is usually more room for more traditional speakers to shift the required amount of air. Engine? Maybe. Horn? Definitely.