I have a completely Google-free Android, and never had a problem. Is it really that bad to install an app? I like the choice.
And uninstalling an app is impossible on stock Android, if that app is made by Google.To achieve that I had to unlock the boot loader of my phone, for which there was no official method.
Meanwhile on iOS I can use the default mail and calendar apps that work fine and my password manager integrates perfectly with the os, while I don't need to use iCloud at all if I don't want to.
Those 3 apps weren't the only reason to switch from os, but they did make the choice for, and switching to, iOS a lot easier.
You need to find instructions based on your specific device. Each one is different.
GrapheneOS.org