A 25 watt amplifier, constantly driven to clipping, is more dangerous than a 250 watt amplifier that is never taxed. Of course, let reason prevail. I am not saying that speakers can handle endless input, they cannot. However, extra power does not mean that speaker damage is bound to occur. If common sense is used, any size amplifier can be employed.
Many factors influence amplifier choice.
In an extreme example, one might own an inefficient loudspeaker, have a very large room, and like to listen to pipe organ music at realistic levels. The next listener, with the same speaker, may have a much smaller room, and prefers chamber music at background levels. Here, power requirements might be only one tenth to one-fourth those required in the previous illustration. Requirements do vary widely. It is wise to take all factors into account before making a decision regarding the amount of power necessary for your situation.