At a "guided internship".

Task: Develop a complete web application form

Was assigned to a team of 7 where all are "Frontend Developers" who have never heard terms like "bootstrap" or "mobile-first web pages".
That aside, all are seniors in age and qualifications, hence me telling them something to do is "ordering them around". And if I tell them to leave things to me, they be like "No, we wanna contribute and do the Frontend, as these things don't matter, inline css just works fine". 🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️

Why Lord? Just why?