The reason Justin Sun gave for Tron to be a better one are:
|Comparison||TRON (TRX)||Ethereum (ETH)|
|Transaction per second (TPS)||10,000||25|
|Additional coin issuance||None before January 2021||Continues issuance|
|Coin burn||Consistent coin burn||No coin burn|
|VM language support||Java||Solidity|
|DApp users||100 million||Very small|
|Mobile development||Experienced mobile developers||None|
|Developer rewards||1 Billion||None|
|Delegate rewards||100 million||None|
|Compatibility||Supports pluggable VM interface compatible EVM||Only EVM|
and Vitalik answered with another reason why TRON is better than Ethereum:
8. Better white paper writing capability (Ctrl+C + Ctrl+V much higher efficiency than keyboard typing new content)
— Vitalik “Not giving away ETH” Buterin (@VitalikButerin) April 6, 2018
Of course, Ctrl+C means copying & Ctrl+V means pasting the exact concept of Ethereum!
Ethereum, undoubtedly has practical use cases. A number of Dapps are being built on top of it. Tron, on the other hand, is still in the development phase and this tweet of Justin Sun seems a bit out of line at the moment.
How the crypto world responds to this newly started war between two, is yet to be discovered!