In general people over-generalize. It gets very old. Calling LN a failure is an example. It has issues. It may not be the solution to scaling bitcoin to mass adoption. Only time will tell but it is a step on the road and is working for many bitcoiners today.

Here's some advice. If you are gonna call something a failure you first need to consider what were its stated goals. Has it failed to meet them? If so, is there anything to be learned from it? If both are no then yeah, its a failure. That however is rare.

Lightning is infinitely reusable chain transactions, nothing more or less when you boil it down. People that don't understand Bitcoin, or don't want to use the chain at all, get mad when it doesn't behave more like an SQL database than the chain.

NGU is Bitcoin's core value proposition, payments are a tougher sell since most of the world has largely satisfactory payment rails.

Information warfare is the biggest factor. Hundreds of millions of dollars have been invested into affinity scams like Fedimints and Liquid, that money buys opinions more than it buys developers.

Ultimately lightning will probably become the glue between different ways of “sharing” UTXOs, if all these different options can speak lightning they become interoperable allowing for instance payments with minimal on-chain fees. Just like the base layer isn’t for coffee payments, eventually neither will lightning. The fees associated with opening and closing channels becomes economically when the amount of transaction across those channels goes up a ton. If these channels are connecting lots of “shared” UTXOs solutions, they make a lot of sense. Right now it’s hard to see this as we’re still in the process of building out and deciding the best way to do “shared” UTXOs, cheapest way is just have an sql db and be a custodian (but is of course not ideal for all the reasons). fedimint is a step in the right direction which doesn’t require a base layer chain and gives added privacy and reduces rug pull risk vs having a single custodian, but there are still issues with that solution. There are other options in the pipeline that might be possible on the base layer, however, any changes to the base layer take time (which is a good thing). At the end of the day, the question becomes “are the fees I’m paying for opening + closing a channel worth the economic benefits I get from having it” which is a pretty reasonable incentive. Early days, lightning is still a child, at ~5 years old, compared to many of the tools we use in tech today.

F.U.D.

In all aspects of life these impatient & limited attention days everything is a failure unless its perfect for everyone everywhere instantaneously. Millions of people regularly use lightning successfully, but its certainly not perfect. Nothing is perfect. BTC onchain isn't perfect. LN and BTC are just better than fiat, but have limits and tradeoffs. No one said they were perfect. Go back and read the LN white paper. Most issues people are raging about today were in the original white paper years ago. Let's try to be realistic and celebrate incremental improvements by hardworking companies and devs. The fiat system is the result of centuries of work by countless people and it still sucks. By those standards we are just getting started.

Probably because of the low or static volume on Bitcoin on Lightning

Segwit was pitched as a partial block size increase that would allow LN. It was widely accepted as a response to high fees in 2017. LN was going to enable the planet to use BTC at scale, no more high fees onchain. It was the ultimate scaling solution.

Turns out segwit would become a major CAUSE of high fees in 2023 (inscriptions). LN fees have risen in response to chain fees. Its clear that still not everyone on the planet can have a UTXO, LN didn't solve that. As LN tooling was built out, its clear that noncustodial LN is really hard if you're not already a systems admin. This led to many LN wallets being custodial.

The LN white paper makes it clear that the "FULL" version of LN will not be possible until Covenants. So, the LN we know and love is still just beta/incomplete pending yet another soft fork. Many in the "ossify now" crowd view LN as an excuse to keep forking BTC and introduce more unintended "attacks" to the base layer, just so everyone can use a custodian or federation for payments.

The Bitcoin white paper declares BTC as peer to peer, no middlemen, no financial institutions. LN is literally built for routing thru middlemen and hub and spoke "mega banks" issuing most of the liquidity. So many see the LN as anti bitcoin.

All the foundational/major critiques are contained here:

Lightning really saved my ass when I needed to make a few bucks quickly and even if some other scaling solution is ultimately adopted I will probably look at this time fondly like the old timers and usenet

Let's say you open a channel for an extremely high fee if $1000. If you use it once or twice its expensive. But if you use it10k times it is not.

Non-custodial Lightning is too complicated to set up, run and maintain, for most "normal" (non-developer / non-sysadmin) people.

As I type this, I am resending a Lightning Payment (which has "Queued" for the past 5 minutes) after the first attempt failed.

The issue of high transaction fees on the main chain is a concern, but there is not much that can be done. Bitcoin is for everyone, for good and for bad. The only problem I see with the Lightning Network is the issue of opening/closing channels. I think it is a barrier to adoption, but I also don't know of any better solution, if there is one.