I agree with some of your points especially about privacy. Things like Client-side Validation, STARK proofs, Rollups, and MimbleWimble are interesting to me because they're much smaller, don't require storing all data forever, or even on-chain at all

But LN does comes with a lot of unique baggage that L1s don't have:

-requires funded channels to even receive or send to begin with (very inconvenient, unintuitive, and annoying)

-limited in the amount you can send without your transaction failing

-no static addresses or offline receiving

-can be force closed onto the base chain against your will (losing money and time)

-can be rugged if your node is offline (or the LSPs node that you are using)

You can use 0-confs for 99.9% of transactions on BCH for instant payments. It's much safer than 0-conf on BTC because they don't have Replace-By-Fee and stuck with first seen rule. BCH also has Double-Spend Proofs that make it much more difficult to double spend. I think BTC really fucked up going full RBF.

Decentralization is not a binary. Something can be decentralized enough to evade capture. There is also the question of diminishing returns. Does every single user really have to run a node? Most BTC users right now don't run nodes and I'm sure you consider nodes distributed enough. Where is the goldilocks zone? Small world network topologies are probably the best bang for buck

There's also different aspects of decentralization. For example, node software and consensus process for BCH is less centralized than BTC. There are 5 major node softwares that are used for BCH. While 99.9% of BTC nodes run Bitcoin Core and Core acts very much as defacto gatekeepers