Great question! I studied mechanical engineering in college, and was surrounded by other people who also were interested in mechanical engineering! I would say that engineering in general was a popular subject, but mechanical engineering was also one of the larger majors.
What I loved about mechanical engineering was actually the spectrum of people who study the field, and the many options that you have in "specializations". I have friends from college who have the same degree, but are doing completely different full-time work! For example, I started working in manufacturing companies, but then moved towards design and management in my own career. I know many others that choose to explore careers in industry working on mechatronics, robotics, manufacturing, or designing propulsion system (jet engines etc.) or biomechanical parts (prosthetics etc). Beyond that, there are even more options in academia, including doing research for universities, studying fluids or heat transfer in materials and parts. I included a link below to the Stanford department of mechanical engineering for reference, but it might be a great place to start exploring all the vast opportunities in the field.
Good luck on your career and college journey!