I also like using the kana swipe keyboard. Because of how romaji works, you need two keystrokes for every one kana, whereas with kana swipe you only need to press and swipe for each kana, so it feels like it should be faster in the long run if you practice it. To be fair, I’ve never liked typing on phones so I’m pretty slow either way, but I think if you get used to kana swipe it’ll be faster after you get past the awkwardness. I’m not exactly fast on the kana swipe, but it feels a lot better than the romaji one to me personally.
As for what Japanese people use, I’ve heard that on mobile there are people who use kana swipe and those who prefer the romaji input (there was one of those “Ask Japanese” interviews on youtube about it if I recall correctly, you can probably look it up), so I think you’re justified using whichever one is faster and/or more comfortable for you.