"too complicated" is a weird way to say "provides a concise and consistent way to model superficially diverse phenomena and show how similar they really are" .
matrices over reals are ok especially if you keep to SO(n) but you can get very weird maths as polynomial quotients. they do not look to me like they are very similar. complex plane and extensions of all kinds of weird. seems hacky rather than illuminating to me. but then i only really like complex numbers as a field since analytic functions are so nice
Complex numbers being equivalent to R[X]/(1+X^2) and dual numbers being equivalent to R[X]/(X^2).