I have the centurion 541 cooler master case and I'm going to buy new parts to replace the old parts should I get a new case a friend told me that I should because it has bad airflow or I think it because it doesn't have enough holes for the air so I am wondering if I should toss the case or keep it
What components are you looking to place in the case? All it needs to do is fit the components in it and have plenty of airflow to get the hot air out of the case. If you want more space for more expandability in the future and the best cable management possible, then yea maybe upgrade the case, but it's up to your preference as long as those new components fit. I mean if you're putting 64GB of 3600mhz ram, AMD Threadripper and RTX 2080TI in it, then you might want to consider buying a new case. But if you're putting a more moderate/average gaming PC in it, then maybe not. I mean, hell, Linus from Linus Tech Tips put a RTX 20 series card in a pretty small case for a VR streaming pc.
The Centurion 541 by Cooler Master is an old case. I would recommend purchasing a new case to get the modern features. For starters, new cases have many channels for routing cables and hiding them away cleanly. New cases will also typically have a window on the left side so that you can showcase your components. They will also have USB 3.xx which will mean faster throughput for your devices and portable storage that are USB 3.xx compatible. Many modern cases also focus on airflow, so it will not be difficult to find a case with a good amount of ventilation. Lastly, modern cases also focus on aesthetics. In the past, manufactures did not seem to care too much on how the case looked. Now you can find one that looks great as well as being feature-rich and functional.
On a side-note, be sure to compare the max CPU cooler height and the max GPU length designated by the case manufacturer to the height and length of the cooler and GPU that you are looking to purchase. Nothing worse than getting ready to build and finding that your components don't fit!