Practical lessons can be lively and fun, but children often fail to really learn anything
The basis of the scientific method is to discover by doing. Scientists suggest a hypothesis and then subject it to experimental tests. Over time, knowledge is acquired.
Many people would believe this to be the best method by which schoolchildren can acquire scientific knowledge. The thrill of discovery should be more effective, in theory, than being told about something. And practical lessons have the added benefit of being “fun”.