No it's not due to any advancements in the field. You only apply about 5% of what you learn in uni anyway, and the rest you learn on the job. 3 years is nothing anyway. If it was 30 years ago when computers weren't mainstream yet, then maybe.
The issue is why you chose not to get a job in engineering in the first place. You'd need to have to have a good explanation of why you did chose to do something else first, and are now deciding to change back into engineering. It gives the impression that you weren't interested in engineering to begin with. So why would u be interested in it after 3yrs? Is it only because your current job sucks? Etc. It'd make them uncertain about what you really want to do. If you were say, working part time for those 3yrs, you could say that you've been job hunting for an engineering job all this time. But if you were in another serious career, e.g. as a financial analyst or something, then you'd have to do a fair bit of convincing.
When it comes to graduate-level engineering roles, it's never about what you know, because grads know jack all anyway. The degree just shows that you're not a potato and show some signs of intelligent life. It's about whether you'll fit, and whether you seem like someone who will stay and contribute, or whether your someone who will just piss off after a few years. If I reviewed a CV and the applicant was in some random ass field for the last 3yrs, chances are I would toss it aside unless their CV was impeccable and/or their cover letter was able to convince me otherwise.