Worst case, a client or protocol flaw is found, and everyone in the world is expected to close their channels (settle) at 7 transactions per second?
Please. Bitcoin Cash is the large block scaling we've needed all along.
Furthermore, 2-3% of all transactions on many of these systems are fraudulent, but the payment systems ACCEPT This as an acceptable level of fraud and cover the expenses, in order for faster transactions.
Square knows for example it won't be used in coffee shops over another competitor if Square on average takes 20 seconds longer to process metadata in conjunction with the transaction itself to see if its an attempt/fraudulent charge, so they consciously cut corners here and accept this liability so we can all get coffee 8x a day.
This is why bitcoin has industry standard confirmation blocks so the network can address and blacklist attempts at doubles spends and keep a master chain.
This is basic blockchain 101 compared to standard knowledge of onboarding to every en masse payment system we all anecdotally have experience with layered digital transaction technology and the losses associated with that.
The lightening network is as mentioned above with links, rapidly evolving to expediate this while still maintaining the underlying benefits of transaction consensus that avoids fraud.
You may deal with fraudulent exchanges as you will do with fraud around any new technology (heard of the internet before? there were lots of sites for fraud, and much worse when it came out, and still are, we just all get smarter about what we click, and hopefully in this case, who we throw our money at, which you should be doing anyways for any new technology...) but the fraud here is associated with like top ranked comment said, not the protocol but the flurry of business activity around it, and is really null and void to the technical conversation itself, which is really what evolves communities like this past these handwavy statements...
I really don't mind constructive criticism of blockchain based technologies, but the issue is the conversation rarely evolved because of cargo culting statements like this that ignorethe very benefits of moving to a blockchain based payment system.
Regardless, your point only further proves that the bottleneck for onboarding users to lightening en masse is, if a problem at all, not one unique to that network, or any other payment system we currently use.
You are forgetting concurrency. A bank doesn't stop processing transactions for 7 days while opening 1 account. Thousands, millions, or more accounts can be opened concurrently. If account demand skyrockets more branches can be added, more tellers hired, banks can compete on efficiency of service.
Bitcoin's 7 TPS rate limit is global and immutable (without a fork). You cannot add more nodes to satisfy demand. You cannot add more hash power to satisfy demand. You get 7 TPS or you try to get consensus on upgrading (which almost always means a fork, which ironically is an extreme form of fiscal stimulus as it doubles monetary supply).
Even if crypto were were to gain mass adoption it weight not be btc in it's current form that wins that lottery.
Big blockers are new flat earthers.
Btc’s current limits are far from optimal but layer2 itself is working great especially on other chains.