Simple Or Complicated
Keep it simple if you are ahead. And if not, don't.
That's for overall strategy. As far as joseki choice is concerned, a good idea is to play the simplest variation that is a good strategic fit with the overall position.
On the other hand one shouldn't compromise into playing inferior plays. In order to become stronger one should refuse to make certain kinds of technically poor plays, such as bad shape or low plays or aji keshi. Refusing means that you find some other way: resistance or tenuki or sacrifice. These may seem complex - that in part is psychological and in part the need to acquire unfamiliar thinking patterns.
Simplifying a complex middle game into a won endgame is naturally a good idea. It does require considerable strength, and also explains why positional judgement plays a major role in the practical ability of strong players.