The design industry in Malaysia is growing. However it is getting more competitive as there are more more people who are interested in it. As you've not specified what kind of design, it's really hard for me to give you specific thoughts on it. if you are looking for money, doing design will not give you that. Certain design jobs can give a stable income, eg: architecture/interiors but don't expect much from it unless you go above & beyond by expanding to your own business.

HOWEVER, pursuing a degree in design will not limit your future to just design jobs, I've known many friends who's done design in their studies but are currently working in various fields eg: tourism, automotive, business etc.

Scoring a job on the other hand boils down to yourself, personality, communications & problem solving plays a bigger role rather than what is on your certification.

Hope it helps, my background is interior design btw.

It shouldn't be an issue, as long as you have the interest & passion, there are many ways to make side hustle while working a main job. I myself learned some simple web coding & website building during my study days for a small online retail when I had any free time. Extra skills are always valuable as any diversification will not hurt your future growth.

With youtube etc, its honestly really easy to learn the basic software you need for illustration. Not all artist have a degree & not all degree holders become an artist. You can always pick up small freelance jobs online if you want to explore further. There are a number of websites that offer users to post their services for a fee and i've seen ranges from rm5/hour up to rm100/hour depending on how experience they are.

Just my 2 cents. hope it helps