Sending ETH from L1 to and L2 for cold storage, any cons?

want to send eth from hdw wallet to an L2, I mostly hold long term but once in a while I want to swap to stablecoin and the L1 gas fees are just too crazy sometimes that I avoid swapping.

• any downsides on keeping it in an L2?
• is security the same as mainnet?
• I'm considering Optimism for it, is that good?
• Should i use the official bridge or is there something cheaper and also secure

thank you!