Okay starting to make sense.
You live in Ohio based on your profile, so you have no safety inspection required every year or other year. Therefore, people can bastardize their vehicles like this and sell them instead of being forced to deal with the problems pre-inspection time.

I suspect the bulbs were pulled for the exact reason you / we have determined. There is really no other explanation for not wanting to have bulbs in your reverse light assemblies. It's not something you as a buyer would notice if you were alone because you can't be in the driver seat and behind the car the same time. It is something I never thought to check when buying a used car.

It gave me the idea to write down a comprehensive list of questions to be given to a potential seller to answer in writing and sign stating everything on this sheet constitutes disclosure of all known issues with the vehicle. I would then combine that with a standard statement that the purchaser is buying the vehicle noted above as is with no warranty unless you can get one this covers both the seller and the purchaser. If there's anything the seller conveniently forgot to note, it is documented and signed that they did not disclose said issue. Oops is not illegal term.

The seller's hiding problems probably won't want to have anything to do with you and that's the idea. In your case, there is no way to claim you didn't know your reverse lights didn't work because there were no bulbs in the sockets which you took out meeting the seller.

Hopefully none of this is necessary for your situation but please know that your experience has motivated me to write up something I wanted to do for about 15 years to assist others and keep them from getting screwed by unscrupulous ****s when buying cars used.