So here’s the deal. For most companies, your school doesn’t matter, and your GPA only matters insofar as they can be sure you are on pace to graduate; after graduation, it doesn’t really matter - your work experience will become the primary factor in future employment.
HOWEVER, if you are interested in top companies, it starts to matter. There are always exceptions and alternative routes into big / top tier companies, but the straightest shot is through target schools. For example, if you are interested in working for Goldman Sachs, you may have a hard time if you go to a small liberal arts school - even the biggest companies do not have the resources to recruit at all colleges, and some companies only hire via on campus recruitment. So your school will matter in determining who recruits you.
Your GPA matters for companies recruiting at your school. So, once a company has decided to recruit at your school, they will have limited interview slots, and GPA is an easy screening tool. With that said, companies generally don’t control for GPA within their target schools. You might see people with lower GPAs at “better” schools, but that is likely because the company just has more slots at the more prestigious school.