How much is Layer 2 really going to help?

I'm a little confused about how L2 comes into play – as in, when/how do you switch between L1 and L2. Where are L2 tokens stored, etc.

For example, lets say I have 10 ETH in Metamask on L1. I want to swap that 10 ETH for WBTC on Uniswap.

My understanding is that it works like this;

• Send my 10 ETH from L1 to L2 (this costs a normal L1 transaction)

• Swap my ETH for WBTC (low L2 fees)

Is that how L2 works? Will I just have L2 balance in my Metamask? Or are my L2 coins stored elsewhere, and I have access to them through Metamask?

I'm still having to pay a L1 fee to do this transaction. Is the idea that eventually most ETH/ERC20 move to L2, and stay there?

If I wanted to swap L1 ETH to L1 WBTC and store in my my ledger – then there'll still be the same amount of L1 transactions?

Thanks 🙂