There are a number of reasons why option spreads are so high. Like you mentioned, liquidity is VERY low compared to stocks. The majority of option contracts do not trade in any given day, so the market maker has to have a wide spread to protect themselves. Even the most popular options, such as at-the-money options on the QQQs, trade about 10,000-30,000 contracts a day, which is miniscule compared to stocks.
Retail investors cannot post their own bid/asks so this contributes to the high spread. In addition, remember that options are a zero-sum game. Meaning for every dollar you make, someone else has to lose the same amount. You can be sure that the market makers will price options in their favor.
I doubt options will ever reach the tight spreads of stocks if only because there are so many of them. Each stock can have dozens of option contracts(puts, calls) at various prices for a given month. Extrapolate that over different monthly contracts, and you'll see why liquidity is so low.