Why can't dealers just list the accurate TOTAL prices for used cars?

When used car dealerships list cash sale cars, what is the reason to surprise a
customer with a thousand dollars worth of fees that should have been included in the
advertised price? There is no reason to hold back that number.  

Obviously when a used car dealer says the price is firm, negotiating is not encouraged.
There's not much wiggle room in used car sales. The dealer only makes money on the
doc fees, so obviously that number is going to be the highest amount that's legal to
charge, and the salesperson is going to say it's not negotiable.  Tax is not negotiable,
nor is the price for registration and title. Fine.  Everybody knows this, so why are we still
playing the stupid games that end with the salesperson writing a secret number on a
piece of paper?    

It would great if dealers would come clean, but I just had two more of these
experiences, where I've shopped and found two cars online to be priced fairly, but in
person, the cars cost $1,000 more to drive home.   

I need a car.  I have cash.  I can't go to a bunch of dealerships because I'm diabetic
and I don't want to get COVID 19 from a salesman who talks to a bunch of random
strangers all day long.  I just want to shop online and if I like the car, I want to test drive
it and pay for it.  It's ridiculous that I can't just buy a car like I can buy everything else.

If I went to Fry's because milk was advertised at $1.19 for a gallon, I'd expect to pay
$1.19 at the store.  I would not be happy to see that the milk actually cost $1.78, or
$1.95, or $2.38 thanks to fees and taxes.

Maybe you'd all sell more cars that way.