Is there additional risk with leaving a token on Arbitrum instead of mainnet?

I'm currently using Arbitrum to purchase rETH (Rocket Pool ETH) due to lower fees. Occassionally I would bridge rETH back to Ethereum mainnet for self-custody. What I'm unsure about is whether leaving rETH on Arbitrum has any risk I'm unaware of. From my understanding, Arbitrum is still quite centralized at the moment. They are also relatively new so vulnerabilities in the codebase might not be found yet. Aside from those factors, anyone know of other risks for holding tokens on Arbitrum?