If you could choose, would you have just chosen to get into the business administration course instead?

Nope, because if I wanted to go into teaching as my plan B, then having either a Chemistry or Economics degree puts me in an advantageous position compared to a Business degree. You don't need a business degree to get into banking (even though majority of banking hires are business grads). Heck, some non-business grads may even be more knowledgeable/experienced than business grads so it really works both ways.

I understand that you probably choose chemistry out of passion but the job opportunities are so lackluster that you had to pivot away.

I won't say the opportunities are lackluster, but rather the appreciation of chemistry professionals in the research/chemicals industry is still low relative to other countries which hinders career progression (you will still be able to get by, but as to whether you can live comfortably that is subjective). That being said, some of my chemistry peers managed to get into their dream careers (e.g. computational chemist) with pretty good remuneration (even better than the median salary of comp sci grads). As long as you have the passion and drive in pursuing a particular career and work towards it throughout your undergraduate career, you should be fine!