So I think launching on iOS first makes perfect sense and here's why.
Part of the problem with talking about Android's market share is that "Android" doesn't mean anything. Hear me out.
If you tell someone you have an iPhone then they pretty much know exactly what you're talking about. It's also pretty safe to say you've got the most recent OS installed, even if your phone is several generations old*.
On the other hand when someone tells you that they have an "Android" phone... well what does that exactly mean? If you asked my mum what kind of phone she has, she would definitely say "Android", but it's a £60 piece of shit that can't run anything. Whereas my brother would also say "Android" but he has the latest flagship Samsung device.
As a developer this is difficult to build for, and more importantly those much lauded market share numbers mean next to nothing. Ok, Android has 75% market share (or whatever the number is), but of that 75% how many of those devices are nasty pieces of shit? I don't have the data (does anyone?) but I'd wager it's high.
Secondarily to that, how many of these devices have the latest OS installed? I've only done a quick google and found some data that suggests, as of 2019, as little as 10% of devices had the latest OS installed**.
At least for a while, it seems that Google had stopped releasing this number due to the embarrassment of it being called out at Apple keynotes***. I'm unsure if this is still the case but according to this article they still don't release OS adoption as a percentage.
The last point, and probably one which is a by-product of all of the above is the fact that iOS users spend twice as much on apps as Android users****. There are many many datasets out there that show this, but I've linked one below anyway.
1: Fractured Android device landscape
2: Fractured Android OS landscape
3: Android users less inclined to spend money
All of the above makes it clear why launching on iOS first is very much the right thing to do.
***Citation: Google embarrassed by OS uptake numbers
****Citation: Apple users spend twice as much as Android users