but assume we have global adoption, so BTC price is then very very high, it is obvious that happen due to full deflation nature of Bitcoin. So we need pay for create/close/deposit channel on-chain in BTC, with 1MB block size fees will be very high, several dozen or even several hundred $ per transaction, so to be worth do something we need send a lot of money to channel, or buy for cash from someone face2face/online that send as directly through LN.
Firstly, maximum block size isn't 1MB, but uses 4 million weight unit instead. Basically it means current maximum block size are between 1-4MB, even though the average is about 2-2.5MB.
Few assumption that
might better happened :
1. Increase maximum block size/weight
2. Lower default transaction fees
3. Add small fraction into Bitcoin to allow even lower transaction fees
4. Compress transaction size, even though it's already on development
Next problem is that LN need use large HUBs to works most efficient, so owners of that HUBs probably will be exchange, financial institutes, just guys with a lot of money, is that not short way to KYC by this HUBs?
You can choose not to connect to/route through malicious hub/node
LN wont help that much to allow using bitcoin as normal currency. But we have at liest 1000 coins made only for transactions. For sure there are dozen with code that is scalable enough. Will that destroy oryginal bitcoin?
well we can use this coin for everyday usage and bitcoin as store of value (like gold) and main crypto exchange coin that every other coin is pared with.
And you better know there are certain trade-off on coins which claim have good on-chain scaling which the developer never tell