There is more technical such as invoice, network and of course, must integrate with full bitcoin node, so if the website server is like potatoes, there be a lack. and It should need more employees than a website without a lightning network, so it needs more budget for pay salary. But which the innovation, that possible they will be more bring new users or not at all where many people still didn't understand.

I hope you don't break the forum rules, Multiple posts like the 3 post above is forbidden, If you want to answer the multiple, use quote.