I also disagree with that "objective" definition of loli, as it includes a number of decidedly not-loli girls. I can't accept any definition which classifies Nott from Critical Role as a loli.
I also disagree with the idea that the loli needs to be sexualized. It's a way of referring to childlike anime girls, sex isn't actually part of it any more than it is for Onee-san type characters. It'd be like saying Maddie Fenton isn't a MILF because she isn't sexualized in the show.
Personally I think loli is more of an overarching term for a whole clade of character types, which even then can be divided into two supergroups before all being grouped into lolis. I'd give these five groupings:
-True Lolis (Must be short, flat-chested, and proportioned like children with regards to the media they're in - IRL standards applied to anime would have 90% of anime characters wind up as kids, which is obviously not true.)
--Actual Children
---These are characters who are either actually the age they appear in-universe (500 year old vampire? No, she's nine.), or who behave like children (not childish, actually like children). That girl from Kodomo no Jikan, or (if I'm right, I don't play Genshin) Klee.
--Teen Lolis
---Characters who are technically 18 or whatever, and behave like teenagers, but they're drawn like they're preteens. Think Taiga Aisaka.
--Lolibabas
---Could plausibly be split again into loli MILFs and proper lolibabas, but given loli MILFs are so rare I don't see any point. This grouping is for lolis who behave like old ladies and aren't in-universe kids. The GILF loli from 100 kanojo is a good example, or Senko-san.
-False Lolis (Must be short, and EITHER flat-chested or proportioned like a child, but NOT both.)
--Oppai Lolis
---These are characters who are proportioned like children and are short, but have massive honkers. May or may not be an actual child in-universe.
--Petites
---Characters who are short and flat, but who aren't proportioned like a child (at least most of the time - you know how anime changes from shot to shot). Think Louise from Familiar of Zero; she's often lumped in with lolis, but if you actually sit and look at her, the way she's drawn is like a grown woman, she's just short and flat as fuck. Her legs are way too long and her head too small to be a proper loli though, she doesn't look anything like a kid. Yukari, the purple-haired girl from Yuyushiki, is also a good example. They might have very small breasts too.
I think Shortstacks and Chibi characters might be related, but I don't think I'd ever lump either under the banner of Lolis. They're just too far from it.