Most of Google's apps on iOS are better than Apple's and most iPhone users who I know are aware of it. But they also don't visit this site because Apple isn't a religion to them.
Let's see on my iPhone...
1) Using Apple Maps over Google Maps
2) Only using gmail because that's the only mail app my work mail account works with. It's spark for the rest.
3) Youtube app - what choice is there really, when Google has crippled pretty much every other third party YouTube app (and only recently introduced PIP, when Protube already supported it way back in 2016).
4) Siri vs Google Assistant is kinda unfair since only one is baked into the OS, which effectively nullifies any advantage Google may have on a technological level, since users can't readily access it either way. It's Siri all the way on my iPhone, iPad and Apple Watch.
5) Youtube Music - only have it because of Youtube Premium, and this thing is a joke.
6) Google Drive apps - continue to suck in terms of functionality and only recently supported split-screen. Use it because I have to, not because I want to.
7) Safari vs Chrome (no contest here). Running DDG as my search engine, have Firefox Focus and Lockdown working overtime to block all those trackers, recently purchased Amplosion to strip out all those annoying AMP article links.
8) Google Photos - no reason to use it over iCloud photo library.
9) Google Earth - use it on my iPad for my Social Studies lessons from time to time, but otherwise, no real reason to open the app on normal days
10) Google Calendar - I am using Fantastical. Only open Google Calendar because my school implemented a resource booking system via the service. Otherwise, it's also pretty bare bones and I am not really seeing the allure.
I can't think of a single google-made app on my iOS devices that I am using out because I want to, vs me installing it either due to work-related purposes or because it offers functionality that can't be replicated elsewhere. Given a choice between a google-made app and some other alternative, I will likely opt for the alternative every single time.
They are that overrated, and they are that bad. The underlying infrastructure may be fantastic, but their software design chops really leave much to be desired, IMO.