Is it worth buying GPT credits form openAi for personal use rather than just using ChatGPT, if so why? I'm wondering if having access to the system role could m

Is it worth buying GPT credits form openAi for personal use rather than just using ChatGPT, if so why? I'm wondering if having access to the system role could make it more helpful and useful? Trying to feed ChatGPT info, but it still eventually ignore it or it becomes too much for it and then it just reverts to being generic.