You have to learn skills that you will never use, because, inevitably, you start to forget things after graduation. If you haven’t learned anything extra, you will have to forget skills that you actually need, such as how to feed yourself. So stock up on useless knowledge while you can!
In any case, if you don’t learn algebra, that guarantees that you won’t use it in the real world. If you do learn it, though, you have the option of using it if you want to.
One of the main advantages of algebra is that you can do less memorizing. If you know one form of an equation, you can derive the other forms. For basic electricity (Ohm’s Law) for example, if you know E=IR, then you don’t have to memorize I=E/R and R=E/I, you can easily derive them.
Incidentally, that problem and others like it can also be solved using Snell’s Law (yes, the same law that governs refraction of light). Thus illustrating two points: First, if you understand math well enough, you can solve that problem without using calculus (although you would need trig). Second, with understanding of mathematics, you can see interesting and beautiful relationships between apparently unrelated problems. The beauty that math lets you see, IMHO, is itself enough of a justification for learning math.