Ok thanks. What about these versions, are they correct?
Who DOES live in that house? Mrs. Smith does.
Who DOES like ice cream? Almost everyone does.
What DOES have four tires? An automobile does.
What DOES smell delicious? A chocolate cake does.
Which DOES look the most attractive?
These are grammatical but have a different meaning. They are all follow-up questions to correct wrong information:
Me: That is Lucy's house.
You: No, it's not. She sold it.
Me: Then who does live there?
You: Mr. Smith.
Me: A motorcycle has four tires.
You. No, it doesn't.
Me: How many does it have?
You: Two.
Me: I like the look of that ice cream.
You: Yes, but it's not the most attractive-looking dessert on the menu.
Me: So which does look the most attractive?
You: The pie.
By the way, all the answers to such questions do not have to be 3rd person singular, it can also be plural. So why do we have to put "s" to the verbs of subject questions in simple present tense. Why do "who-which-what" always treated as singular in subject questions in this tense?
A: Who helps you when you need help?
B: My friends
I know all languages have their own structure-logic but the logic of my native language makes me think that this structure is weird.
Yes, it is weird. Who, what, and which are not singular or plural because they are not exactly nouns. They are place-holders for unknown nouns. When we use them with verbs, we treat them as singular nouns, just to be consistent.
I know it seems strange, but it works. You'll get used to it!