Millions for development? Do you have any sources? I’d like to read about it. Thanks

Watching videos from the most recent Bitcoin conference is a good way to get updated on recent development changes to the protocol, lightning included. Bitcoin Magazine if you prefer reading to watching. Github if you prefer reading code to words.

I don't have a specific source to cite here, just am generally aware of what's going on in the bitcoin space. Lightning labs is the main company building the protocol, they've raised 86 million in funding, though not this year. There's dozens of lightning wallets, some of which are supported/published by companies like ACINQ whose investment capital measures in the tens of millions. Tons of stuff is being built on it. And more payment providers are integrating lightning: Strike and Cash App are the two major ones. Coinbase recently announced they will be adding support for it, Kraken and most other exchanges already support it. There's a lot of FUD about lightning, there are some valid critiques to be made for it as a "universal scaling strategy", but generally speaking, it works well and does what it's supposed to and has plenty of room to scale. There are proposals (channel factories etc) which will massively help with scaling as well.

Likely there will be more than one L2 in the future to optimize for different use cases. But for large orgs who frequently need to move liquidity around, solutions like lightning are excellent. They can settle their accounts with other orgs and their customers instantly. Think banks, online retailers, online marketplaces, etc. This leaves less money "in flight" and at risk. And it can also be used for micro-transactions for everyday people. A bunch of funding just got allocated to Ark as well, which is another L2 solution similar to but different from lightning. Fedimint is another project/proposal to look at if you are researching all this.