It depends on what your goals are, and what you are doing in the time you should be studying.

If you are applying to higher studies, then it is dangerous to ignore academics. The simple logic is that if you choose to ignore your professors & books during undergrad, what is the guarantee that you won't do the same in grad school? It is basically about respecting the system you are in. Do not ever ignore your academics if you plan to do a master's/PhD.

If you plan to work in the industry, the academics matter less. However, it would be really important to show them that you used that time to improve your knowledge. For instance, if you got low scores in a couple of courses while contributing to a major open source project or got innovation awards for your idea, the recruiter might ignore the lower scores. However, if you spend that time studying and watching a few more movies with your girlfriend/boyfriend, you will find trouble when the time comes.

In general, do not ignore academics. It is fairly easy to get decent grades in most universities if you just spent the last 2 weeks before the exams. That is the base level commitment. Thus, you could have spent 3 months on the ML project with the professor and tried to compensate by studying hard in the days before the exam. You might not get the top grades, but you will get reasonable grades that when combined with the quality projects you are building will be great for the recruiter.

No one will say CGPA doesn't matter. They would be lying if they said so. It does play a role in starting your career and has little value if you consider life as a whole. But how you start your career matters a lot. CGPA does open gates to many opportunities, be it internships for college projects or LOR from professor MS admission abroad universities.

In short, you have to balance what you like and what others about you in the professional world are likeable. From my experience, I would say maintaining a cgpa of 8 is damn easy with a little effort. I have a CGPA of at least 8-8.5. Still, it would leave you plenty of time to pursue your other endeavours

Both GPA and CGPA will be displayed on your mark sheet, influencing your applications for higher studies abroad, placements and scholarships. CGPA is vital for cut-offs at several scholarships and university courses. Students often fall short of the criteria by simple decimal numbers.

Have you looked into other options?

I wish to pursue ( STEM ) Masters in marketing or finance in US , Australia (can recommended other countries) PLEASE SUGGEST SOME UNIVERSITIES?