This is a well organized content. I would love to expanciate on the disadvantages you mentioned above.

Waste of energy

The use of blockchain requires a lot of power and energy. We cannot really say that it is a waste. This energy or power required to run a blockchain cannot be afforded by all organizations and even for some underdeveloped countries.

not so easy to use

This is very true. Blockchain is a complex technology that requires a lot of intelligence to use. It's use requires that a person is educated to a certain level. Our illiterate family members may find it difficult to use.

Facility for illicit operations

There so many fraudulent activities associated with the use of blockchain. The government or any organization can hardly control frauds when it comes to using blockchain because of the anonymous nature of the technology.