What about Direct Retailers Adoption of Bitcoin?

No, not via Bitrefill.

Do you guys foresee a day when any of the largest retailers (something like Costco, Walmart, Amazon or Home Depot) takes Bitcoin/Lightning without ridiculous mark ups?

How does the timeline look like? I know a lot of custody infrastructure has be managed and built to fit the scale. If you think about it Visa and master card took their own sweet times to become as ubiquitous as well, as many retailers stuck to only cash for a long time.

So where do you guys see Bitcoin/lightning as a payment method?

I mean, look, if your grandma is asking why Bitcoin, is not it much easier to tell her

You can buy your grocercies at Walmart with it

than having to explain Satoshi's white paper? If I understand one thing, it is, most laymen care far more about the process (how to) than the principle (why).

So unless the how to use bitcoin part gets simpler, it is a tough ride ahead.