The game is not worth the candle

I just came across a phrase I have not seen in a long while - The game is not worth the candle.

I see from Ngram Viewer that the phrase has indeed been in long term decline.

Click to enlarge.

Phrase Finder has a good description of the origins.

This phrase relates to occupations, games etc. that were thought so lacking in merit that it wasn't worth the expense of a candle to create enough light to partake in them. Candles were as significant a drain on household expenses as is the electricity bill today. There are several phrases in English that express regret at having wasted valuable candlelight. The best known is the Biblical 'light under a bushel', which appears in several of the gospels - for example, Luke 11:33 (King James Version), 1611:

No man, when he hath lighted a candle, putteth it in a secret place, neither under a bushel, but on a candlestick, that they which come in may see the light.

Stephen Gosson's The ephemerides of Phialo... And a short apologie of The schoole of abuse, 1579:

"I burnt one candle to seek another, and lost bothe my time and my trauell [work]."

William Lambarde's, Eirenarcha, 1581:

I shal but set a Candle in the Sunshine.

'Not worth the candle' is ultimately of French origin. It appears in Randle Cotgrave's A Dictionarie of the French and English Tongues, 1611, where it is listed as:

"Le jeu ne vaut pas la chandelle."

Cotgrave translated that into English as "it will not quit cost".

The first known printed record of the phrase in English is in Sir William Temple's Works, circa 1690:

"Perhaps the Play is not worth the Candle."

Our world in Data has a good comparison of cost per million lumen between olden times and today. A million lumen in 1800 cost £9,539 per million lumen compared to £2.45 in 2000. Nearly 4,000 time more expensive back then.

If we go back to Shakespeare's day, circa 1600, a million lumen of candle light cost 6,400 times as much.

Your typical incandescent light bulb today costs, depending on bulk etc., about a dollar to buy. Imagine having to pay the equivalent of $6,400 for a light bulb. If you were burn a candle to do something in the evening, it clearly would have to be worth a lot.

I am left wondering whether the decline in the phrase is because nobody uses candles much any more, or whether the decline in the cost of light has been so dramatic that the whole concept is now an unnatural mental model. I am inclined toawrds the latter.