The light bulb was invented in the 19th century, but did not become important until a massive electricity infrastructure was built in the 20th century.
If the joke was about the horrific web design (and it was horrific), I didn't get it.
"Important" is a relative matter of course, and surely light bulbs were not as ubiquitous in 19th century as they were later, but e.g. London had 2.5 million light bulbs at the end of 19th century. That is not insignificant.
If the joke was about the horrific web design (and it was horrific), I didn't get it.