Actually lightning technology has improved the transaction speed of bitcoin and hope to see far more developments to see a much more higher speed than present. Bitcoin will surely dominate but that is far fetch from now. We can only hope that in future if bitcoin is accepted by many countries lightning technology would have advanced to speed bitcoin transactions.
Using Bitcoin , I can wait 3 confirmations and consider a transaction complete after ~30 minutes.
Using Litecoin, I can wait 6 confirmations and consider a transaction complete after ~15 minutes.
Using LN offchain network that timelocks bitcoin or litecoin,
I have to wait whatever the time lock is set too (usually ~2 weeks or longer) for the final transaction to be completed /redeemed onchain.
While LN offchain IOUs are fast, they are still IOUs and not bitcoin, as LN can also work with litecoin and others.
Once LN reaches global acceptance , people will buy the LN IOUs for fiat , and cash out the LN IOU to fiat,
ignoring the underlying blockchain completely.
Where as some people buy btc or ltc and just hold it ,
with LN their is no point to doing this as it main purpose is a payment service where middle men make money off of fees.
Which is why LN users will eventually ignore the underlying blockchain completely, just as people that use checks never bother verifying the financial stability of their banks.
