With regard to security I definitely trust Google, they’re doing incredibly important work on all fronts, with their Pixel hardware, and with things like TLS 1.3 in Chrome, and their focus on hardware security like U2F.
Where I don’t trust them is with privacy, and that’s where the custom software comes in. If you’re running GrapheneOS there’s nothing to worry about.
I haven’t seen any evidence of that.
The big thing is Apple keeps their hardware/software offerings relatively siloed from their services and third party apps. I think their hardware is exceptional, and iOS is great for security. Where it gets less clear is with iCloud: the data that they collect that isn’t End-to-End Encrypted should be for example; and with third party apps, because no privacy/security features on a device are going to prevent you from giving away your data to Facebook or whoever.
Contrast with OEM (Google Play enabled) Android, which is basically just a vehicle to get people using Google Chrome, Google Photos, Google Drive, etc.
Also with the iPod Touch I was more referring to heightened hardware security because it lacks GSM, so cellular tracking methods are completely out of the picture. It’s just iOS and a WiFi module that can be disabled, which is fantastic. There aren’t any phone-like Android devices without cellular capabilities that I’m aware of, and certainly none I’d trust (I mean, I’m sure some Chinese company makes one). And even stepping it up larger there might be some Android tablets that could fill that niche, but I’m not even sure if I trust them. Samsung is basically the only people making Android tablets anymore and their track record with updates is abysmal.