On the scalability issues of onboarding millions of LN mobile clients

The security of Bitcoin is dependent on the assumption that a majority of the economy verifies their incoming transactions using their own full node. However, there have been severe regressions in recent years which could lead to Bitcoin's failure without improvements to the full node ratio. Therefore, all efforts to improve the "full node-less" experience should be avoided. BIP 157 improves privacy of Full Node-less usage but provides no real benefits to full node users compared to more efficient protocols like Stratum/Electrum. The support for BIP 157 in Core is opposed by ZmnSCPxj and a few others. BIP 157 can be implemented as a separate daemon that processes the blocks downloaded by an attached bitcoind. The deployment of BIP157 could lead to an effective DDoS on the full node network if a large number of BIP157 clients arise. Watchtowers can provide light-client services, which is still less than ideal, but better than nothing.