I can't speak with any experience regarding Google's apps. What little I've seen of them hasn't impressed, but I admit I haven't given them a fair chance either. About the only thing that might have captured me would have been a form of love at first sight. Since that didn't happen, I was done.
I've been firmly entrenched in Apple's ecosystem for a very long time, using Apple's native apps. They do everything I ask and expect of them. I came to Apple after a very long stretch in the world of Microsoft - "Customizable" wasn't the word I'd use for Microsoft's apps - yes, a huge set of features/capabilities, but I saw it as bloat and clutter rather than anything that was beneficial to me. I was happy to leave that behind.
We all have a tendency to want a feeling of "home," and when we find our comfortable home, adapting to change isn't easy. i don't know how many Microsoft-to-Apple switchers I've come across over the years who needed Apple's OSes or apps behave in exactly the same way as their familiar Microsoft products. Telling them they could accomplish the same task in a different manner was not enough; even sharing an arguably simpler path to the same end wasn't enough. They wanted Microsoft-on-Apple because it meant less re-learning/adaptation.
Change isn't easy if you're not eager to embrace it, and when it comes to fundamental apps like mail, contacts, calendars, etc. there's near-parity among the apps that support those functions. It's rare to see any app that makes each one every feature easier to use than the competing apps - each tends to have its strengths and weaknesses. There will also be UI differences, and while some of those are functional others are aesthetic. Different tastes for different folks.
So yeah, if you love the app you're with and are highly productive/proficient with it, every difference in a competing app is more likely to be seen as a negative than a positive. It's human nature, but in most cases there's nothing wrong with that.