After careful analysis, I pick Serena in 3.
Serena had tougher opponents along the way including Vee and Pliskobot.
On the other hand Osaka basically had a free ride except for couple of ball bashers in Sablenka and MW (mentally weak) Madison.
But, I like the way she stood her ground against Madison saving 13 BPs and so am giving her a set.
I concur with you but for maybe a bit unexpected reasons.
I don't care much about either player but what I do care about might be somewhat familiar to you: my agenda in my hatred of Court. Court is a classic example of a racist woman. She stands like an eyesore because she made a history in the Australian tennis but with her off court attitude, she'd better not. They named the arena in MEL after her and they regret it now because the name is now controversial, and very justifiably so. It will remain controversial until it is renamed. Evonne Goolagong was put forward as the appropriate tennis woman whose name the arena should bear far more apropriately, and I cannot wait until it happens. I think if Court's record of 24 GSes gets obliterated, said obliteration will help to forget about her, and will make the process of said arena renaming easier. Any player who obliterates said Courts record is my hero, regardless if I like her or not. I don't like Serena very much as I expressed already elsewhere, but obviously I take her far far better than Court.
So, having spelled my reason whom I support, with this little rant above, I should finish: go Serena, and please don't stop here by equaling Court's 24 GCes, the history expects you to take one more step in 2019 and bring your tally to at least 25, and OBLITERATE Court. You can do it!