You don’t have to use linear interpolation, if you don’t like it.
The point of linear interpolation is that it is easier to control (because you don’t have to deal with bezier handles). It is also easier to animate robot-like movement with it or when you need abrupt change of speed.
I think it will be mostly useful for initial “blocking out” of the animation - i.e. when you setup the first poses to get the rough idea how movement will go. You can make entire animation with it, of course, but you’ll probably need more keyframes.
If you need smooth sweeping motion, than bezier will be probably the better idea.
Either way just experiment with interpolation modes and see which one works for you.
To ensure that the animation loopsproperly you’ll need to set extrapolation mode I mentioned.