One reason is the programming language it uses: Cadence. Unlike Solidity, Cadence is resource-oriented and designed for secure and scalable decentralized applications, w/ a robust static language and making it easier to enforce behaviors and interfaces in smart contracts.
Flow is also way more scalable than Ethereum thanks to its multi-node architecture, which means it's a better choice for developers who want to build applications that can handle a high volume of users and transactions and be mainstream. Many figure out that issue way too late.
And let's not forget about security. Flow uses a capability-focused security model that gives smart contracts specific permissions. Makes it harder for attackers to exploit vulnerabilities. Dapps built on Flow are more secure, scalable, and less susceptible to hacks.
It's years ahead, but many haven't realized that yet - we have yet to unveil the full story in a way that makes it obvious that the value being built is inherently strong. If you're a dev looking to build the next generation of dapps, go with Flow.
Also, if you're looking for simpler ways to build dapps, with ready to go APIs for marketplaces, minting, and other use cases on Flow, make sure to check out