Hadronic tau decays remain an excellent laboratory for the study of many aspects of QCD. The inclusive decays have been used as a source of precise information about $\alpha_s$ for the past 20 years. In the search for higher precision, partially triggered by the LHC, several aspects of this determination have been scrutinised in the recent past. The issues that arise are often of a fundamental nature. We will discuss problems pertaining to perturbative and non-perturbative QCD, with emphasis on renormalon singularities, scheme variations, and a novel approach to the violations of quark-hadron duality. The present status of $\alpha_s$ from tau decays and perspectives for the future will be summarised.