Curate, connect, and discover
Just to add to this, the entirety of the core-four/Tim's era of sidekicks are all drawn in incorrect ages at some point (or all the time in Barts' case)
Going off their ages in the original YJ comics, Tim is 2 years younger than Jason Todd (who will be my reference point), Bart and Cassie (I think) are both a year older than Tim (making them 1 year younger than Jason), and lastly KON IS THE SAME AGE AS JASON!
Which is something to think about since Jason is drawn like a man going through a mid-life crises but Kon is still drawn early 20s (or younger.)
Therefore, (going off Jason's' age being 22-23):
Tim: 20-21
Bart and Cassie: 21-22
Kon: 22-23
Personally, I think Kon and Cassie are the only two that are drawn to their correct ages (including Jason) and DC need to get their act together and get everyone's ages in order.
"Bart's aging has always been everywhere so it's not invalid to draw him like this [9-11 years old]."
Incorrect. While Bart's aging has been variable throughout the comics it has always been explained by a very clear and blatant events preceding the aging.
The youngest Bart has been in the comics barring flashbacks, and literal one-off aging time shenanigans, is 12 which was a thing for all of 3 pages then he rapidly aged to 14 and was stable for a long, long time.
Bart did not experience any changes in his aging (baring one gag issue where he was a toddler, and the Sins of Youth arc where he was an adult temporarily) for at least two years comic-time.
After apprehending Superboy Prime, Bart was aged to an adult, against the advisement of Geoff Johns and Mark Waid he spent time as The Flash until he was given a mercy kill.
Bart was brought back to life by Brainiac 5 in Legion of Three Worlds where he was reset back to his original age before he was aged up, landing him around 16-17 years old.
Flashpoint happened and he was taken out of comic continuity.
Bart come BACK into comic continuity but we are uncertain what his age is - and this is also something he himself is noted as saying he's not sure what his age is either. Logically, if he never aged while in the Speed Force then when he popped back out he would still be around 17 years old. This is the youngest he can be. Tim, Cassie and Cissie meanwhile aged around a year since Flashpoint and their ages are nebulous. Kon's age as well is uncertain.
Realistically, the Core Four should be in the 18-20 range at the youngest, but if we're going to be 'fair' and accept the reboot fucked age relationships up - then their last posted ages anywhere from 16-18 would be valid.
Bart is not being drawn anywhere near that age group currently in the current run of The Flash and is consistently being depicted as smaller than Jai. This could be valid, as 13 year olds can be VERY BIG and for some completely at their adult height - but the thing is Bart is being drawn SMALLER than he was pre-Flashpoint.
I am so sorry I am so agitated. Even being FAIR it doesn't add up or make sense.
Fixed typos and an error.