What I can gather from your posts is that you use Apple Mail with your single Gmail account, right? So for you Apple Mail (AM) works like an “envelope” around your Gmail? If this is the case, I can guarantee that you would have a much better experience using a native Gmail app for iOS, such as email labels, much faster notifications for new incoming mail, etc.
You can try it for yourself, using both side by side and see what you prefer.
However, some people here use AM with multiple accounts. For example, my work email is forwarded to my Google mail (accessed via Gmail app) and I also have it setup separately with AM. When someone emails me on my work account, it first pops up in the Gmail app (I see a notification). With AM, on the contrary, I need to physically open the app and manually refresh it, otherwise I will have a badge for incoming mail appearing there the next day, literally. And this is a reasonably simple setup too, i.e. I only have one email account linked to AM. If you imagine someone using it with several email accounts, then things can and do get quite frustrating for people.