Uniswap labs owns the GitHub repo, domain name, and discord servers. If their domain, discord, etc disappears, the project would struggle because their smart contracts are difficult to use without the web apps and it would damage the trust in the project.

Uniswap owners can shut down their website. They can introduce a 100% fee. They can deactivate their contracts.

Yes, people can still use their smart contracts in 5 years, but the adoption of those contracts will quickly decline without uniswap labs.