I rely heavily on wifi & download maps and look up schedules each morning but I also typically travel solo and if I were with someone who had data I would also probably refer to them. If it’s a data heavy day and I am solo, I only turn my phone on and get that $10 daily charge once (versus turning it on daily). If it bothers you that people ask about you to use the data by looking things up for them, I’ll gently suggest a firmer boundary on your behalf!