Lightning's inherent decentralization, wide adoption, and compatibility with UTXO-based technologies could position it as the connective tissue between each L2. It could act as a primary hub for new protocols seeking to bridge to existing ones, helping to avoid the chicken-and-egg problem of adoption that has plagued new protocols in the past.

Source: blog.blockstream.com

Before NWC you would need to use non-universal APIs  in order to make payments on a user’s behalf. Like WebLN, NWC is a public specification that allows ZapPlanner to request payments from a user’s wallet in a common way. It gives consumers the choice to use their own wallet and removes the burden for developers to build custom interfaces.

Source: blog.getalby.com