You are absolutely right. As a cyclist there isn’t really any good way to reliably avoid startling a pedestrian in a mixed environment. Even if you do the even more conscientious thing and you slow all the way down to match speed with them, and then “walk” with their speed for seconds and softly anounce your presence with an “excuse me” there are still some who get startled. I have had people act after all of that as if I tried to murder them. And I totally understand them! From their perspective they were all alone and “all of a sudden” a cyclist poped into existence behind them. And in their subjective reality they have just avoided a collision by jumping out of the way of some “crazy speeding biker”, but that biker only exists in their imagination. An outside observer would see a bike slowly catching up and matching speed with them, with zero chance of collision no matter what they might do, but that is not what they seem to experience.