Yes, the Cryptocurrency exchange business is a multi-dollar business. 

Cryptocurrency, & blockchain-based applications like DeFi, NFTs are booming exponentially from 2021. The cryptocurrency market is growing with its increasing demands. 

These are exact data from coinmarketcap :

• Types of Cryptos: 18,337 
• Number of Exchanges: 468
• Total Market Cap: $1,819,264,993,098

Revenues are generated from the following ways:

• Deposit Fee
• Withdrawal Fee
• Trading Fee
• Listing Fee
• Market Making
• IEO, STO, and ICO Fund Raising