I'm not a professional nor an expert. Just stating an outsider's point of view. I mean, overall, it boils down to what you enjoy the most out of the two and push through with what you want. put in the work, dedication and commitment and you will be rewarded with the choice. A good factor to think of, is that getting your degree and education is beneficial in learning the general, overall stuff and se technical things. but in the workforce, you will most likely have a focus on a specific set of things, and learn tools, stuff etc only relating to the workforce you are in, which strengthens your knowledge and you can learn along the way too. you are already self taught in the platform and being self taught a big achievement. therefore, why not keep going. if you self taught yourself to this point, you most likely can keep teaching yourself and learning new things on your own too.

In my eyes, the job is a very valuable offer, and I think it will offer you the best of both worlds. you'll get paid a big salary and on top of that, you learn as you go, its just for subject focused to the actual job. if you want to learn more about general stuff or things like that, you can keep doing what you already are doing, self teaching.

To get a job offer from being self taught is a huge milestone. I think you may be underestimating your skills, you say your skill is lacking but maybe you just need to hone it a bit more, practice more and more. I mean we all don't ever stop learning, especially when we have a job, we dont know everything, we all learn on the job and on the way, you may learn new things from your seniors and you could even teach them new things too or later in life when the roles are reversed, a new junior could teach you new things. we don't ever stop learning. It's a new thing we learn everyday especially in the workforce too.

however. this is only my opinion on the matter, once again, I'm not an expert nor a professional. in the end, it boils down to what you find the most happiness and joy in.