"security on iOS is very clearly vastly superior and this has been confirmed repeatedly by top security researchers"
The vast majority of this "superiority" only applies because the iOS ecosystem is a walled garden. Android devices typically allow sideloading, which obviously introduces an additional attack vector; reproducing this on iOS (i.e. by jailbreaking) brings you back to the same attack surface.
The other notable difference between iOS and Android security-wise has historically been the ability to selectively accept certain privileges, but recent Android versions have introduced this as well, and even the old permissions model was (and still is) much more up-front and fine-grained about which permissions an app requires. iOS also had (and probably still has) an edge for awhile when it came to OpenBSD-style exploit mitigations IIRC, but Android is getting these too by way of projects like CopperheadOS.
Other than those aspects, there are actually very few major differences (last I checked, at least; I haven't really been following the iOS world, so maybe Apple's done some crazy stuff while I wasn't looking) between their security models. Both implement some form of per-app sandboxing, both default to disallowing root access (in most cases, at least; third-party Android distros have a tendency to ship with root access, usually behind some toggle and/or some management app like SuperSU or whatever the latest hotness is), both default to a locked-down boot environment (in order to defend against rootkits), etc. Both have had their share of security-affecting bugs, too. There's no "clearly vastly superior" about it in either direction, at least on a platform level.
On an ecosystem level, sure; Google doesn't do quite as good a job as Apple when it comes to screening malware (there have been quite a few notorious examples of this), and the ability to sideload apps (as well as the much easier jailbreaking/rooting situation) means that more malware is actually viable. This isn't a security problem in the sense of the platform itself, but rather in the sense of allowing users to shoot themselves in the foot by installing trojans. Like I said above, these exact same problems happen on jailbroken iOS devices, too (I reckon with a very similar frequency, too, but I don't have statistical evidence to back it up, so take that with a grain of salt).