To be perfectly honest with you, it manages to be incredibly rewarding and also completely soul-crushing at the same time.

Some people are fortunate enough to land jobs at really creative studios that produce unique stuff and as a designer you'd get plenty of opportunity to work on satisfying, meaningful projects that allow you to showcase your talent. Or if not the creative satisfaction, you could even land a job at a good respectable corporate that understands and values your contribution and pays you so well that you don't really care about producing bland repetitive work.

Either of those scenarios are totally fine, but unfortunately there are other unsavoury alternatives that are often far more likely. There are a lot of shitty studios that understand nothing about intellectual property theft, they just screenshot shit off shutterstock and get people to replicate it with minor changes like a design sweatshop, and there are shitty companies that are morally and creatively bankrupt and will not value your input at all and make you spend countless hours redoing things that could be easily fixed if they respected your time and used the right vocabulary to describe what they want, which is most often generic cookie-cutter stuff that you could find with any cursory google search.

And if you decide to be a freelance graphic its, that has its own set of nightmares. You get to feel proactive and independent but you will deal with slimy clients from hell.

My point is, the only reason to not be an engineer is if you really dislike it. If you like it even a little bit, it's really worth it. Because you don't necessarily need educational qualification to be a graphic designer, you can always do it on the side or do a certificate course online or just teach yourself later in life and make some extra pocket money. But you DO need qualification to be an engineer, you can't do that on the side just for funsies.