I think Scarlet does as well (unless it is just not drawn in for whatever reason and there's a cg that clarifies that she does have armpit hair that I'm forgetting or unless you are saying Lily goes out of her way to shave her armpits but Scarlet just naturally doesn't have the hair there, etc.)
Sh-shut up dork, Lily's the best!
For reals, though, I had forgotten Scarlett even had an armpit scene. But I can come up with a reasonable explanation for why Scarlett doesn't have any armpit hair:
Just look at ToT pre-3F, even though being just two floors made the game short af, this is probably the most "Bo Wei-ish" ToT has ever been. The game feels like a much more polished version of Bo's previous projects, even though some people will still say that it was lacking in quality. If Bo was being influenced by doskoinpo and Msize, you can't really tell as much at this stage. There was also no Koda yet, so there were no expansions and the community didn't have reasons to be angry at the game's development 24/7.
Now jump to 3F's release and the game suddenly loses a bit of its identity: You can tell Bo was being heavily influenced by Msize when he made 3F, not only because Eliza is basically a ripoff of
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, but also because Bo pretty much copypasted
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into his game (which he then went on to reuse a shitload of times). Now what's something that Msize loves to do in their games? Giving girls hairy armpits. And Eliza coincidentally is the first ToT girl with hairy armpits.
Chances are Yvonne didn't originally have hairy armpits, but because her first armpit scene came after her expansion, once Bo had already decided to jack Msize's style, he
then chose to give her hairy armpits. Yvonne's armpits are conveniently hidden behind zippers, thus enabling Bo to make the pits switch right under our noses without anyone noticing. This is something he couldn't do with Scarlett since she had an armpit attack before 3F and her armpits weren't concealed, unlike Yvonne's. If neither of these two were true then I'm sure Scarlett would also have armpit hair just like everyone else in the game besides Lily.
Lily probably doesn't have armpit hair because she represents a break from the norm for ToT girls, or it could also be because she's supposed to be young and I guess you could see a hairy body as a sign of maturity, I guess? I just don't like body hair because to me it feels primitive and manly. For me it makes sense for someone like Khulan to have a hairy body, but for the rest of the cast? Not so much. I get that some people are into it, though. Not trying to kink shame!