A candle gives 0.5 enchantment power, because of the lack of space it seems little to me. If each candle gave 1 enchantment power it could replace a bookshelf and many more types of "enchantment rooms" could be made.

It seems to me a very good idea that the candles have this property, and they look very good aesthetically with the enchantment table, but currently this has no use.
The only way to have the maximum enchantment level is this:

and as you can see it isn't very attractive.

I don't know if the website has been updated, but candles should have a default power of 1 since 4f97c82.