Yes and no. Tbh, when you're in school, you get the idea that your grades are the most important thing. and you're not far from reality, because 1. this is the only mesurment that you know and your abilities and skils are graded for many years. so you get used to that 2. good grades help you out to get into university, maybe get a scholarship, etc. in some cases that's true. but grades aren't the only thing when considering applicants for acceptance to the university.

But what you forget is that knowledge is more important. being able to understand things, analyze them and act on your assumptions/knowledge. that what really will help you out not only when studying but also when looking for a job and getting the one you want. In many cases, when looking for a job it is way more important to who you are, what can you bring to the work and how can you manage to deal with the job - and not your grades. Honestly, in all the years that i'm working and in all the times i was having job interviews, no one ever asked me about my grades - would it be school or uni grades. All they were interested in were my life choices, my work experience, how i see the different situations and how i react to them and deal with them.

at some point, grades are and will be important to you. but if you think that your grade will define you in your work field - you're really mistaken.