I don't mean to sound stuffy when i say that the beauty of open source is that you are free to build a better alternative...but it is true. Either you can build a better thing that you want, or you can pay someone to do so, etc. That being said, there are existing native clients already. May i direct your attention to: https://www.matrix.org/clients/
I am aware of native clients. Due to being unofficial they often get abandoned and two years ago the list looked differently. What I am talking about is that something simple as chat application should not take gigabyte of memory and incorporate a whole web-browser underneath.