All teachers are language teachers

I opted this course although I'm a Biology teacher as I believe all teachers are language teachers. Having been said that I feel multilingualism is crucial for students in the 21st century. That doesn't mean that people need to speak 'proper British English' until and unless it builds a communication. Mostly the second language English speakers determine why English is a global language in the current world. 'English' as a language had always been more flexible, as you may call it 'American English' or include worlds from 'Hindi' like 'shampoo, jungle and so on' but in this era where bias towards the "native speakers" widely exists, this course didn't build that awareness among the cohort.
Collaboration is essential for lifelong learning which is required not just by the students but also by the teachers or as a matter of fact by everyone. Still, the course lacked to build 'collaboration' among the teachers I was working with. Instead, I felt it was a competitive environment. Even if our classes were graded on our individual improvement rather than comparative, still this fact was not brought up. It would have been wonderful if this course involved group work or group projects and a healthier collaborative environment. We didn't discuss our lesson plans or form learning objectives or learning engagements together instead it was one way within me- my TEFL provider.
Keeping in mind this is a certification, I appreciate that it teaches you a lot in such a short span but there are a very few transferable skills taught. I have seen a common way of teaching displayed by most of all 'TESOL' certified teachers as if certification is turning out productive batches of identical people. There are the essential elements like 'reflection', 'lesson planners', observation, peer review but none in practice happen in its true sense.
If I haven't been taught how to 'reflect' as a teacher how can doing it for 10-15 times make a difference. Same goes with the lesson plans, what inquiry cycle you incorporate, which things come first (backward model or not), why I'm using the template given by TESOL, no discussions on such basic issues, I can't be using the same template throughout my life. So are there any transferable skills through which I can design my own planners in future?
The things I learned are innumerable and I give credit to this course that not being from a teaching background I could easily get into the University of Tsukuba to pursue Masters in International Education with International Baccalaureate (IB Board) Educator certification. Also, It motivated me to pursue teaching as a career and I'm doing an online course-Cambridge Biology Educator certification.