The problem with all those l2 is that bridging is expensive too..
No, it's not. Have already mentioned about it above. All you need is a coin/token on cheaper network/chain and move to cheaper L2s from there, instead of going through ethereum which tend to expensive.
For example, use stealthex (
https://stealthex.io), convert from dogecoin (which is cheap to use) to eth on cheaper l2 like base/arbitrum/optimism/polygon/etc. Convert to eth cause otherwise you will be stuck if you don't have eth to pay for gas fee.
If you have already got funds on cheaper l2 then can bridge from there too, using bridge such as jumper (
https://jumper.exchange). Bridging between l2s is convenient and cheap.