People have realized this a long time ago. The expected configuration is a node-based network like the internet. Messages (money) hop from "router" to "router" until they reach their final destinations through the shortest paths. The "bank" would still be your bitcoin wallet, while your lightning allocation would be like a credit account with every vendor simultaneously. The nodes are routers. The amount you put "at-risk" in lighting only needs to be a minimum amount you need to transact for the day/week/month - and it is not really "at-risk" since there are strong protections built-in.

The general story is that not all transactions are equal. A payment from your cousin for a poker debt doesn't need the fury of a million computers protecting it. Similarly if you have an ongoing relationship with a vendor, and many other examples. In real-life there are vastly differing trust-profiles between transactions. It's ok to trade some security for some efficiency sometimes. It doesn't make sense to treat them all the same.