Why doesn't D block contraction affect the other P block groups 14 15 16 etc
As a property showing d-block contraction, the question cited atomic radius. However, d-block contraction can manifest itself in other properties as well:


$\ce{GeO}$ is described as much more stable than $\ce{SiO}$. $\ce{Sn(II)}$ compounds are described as reducing. [Riedel]
The pentachlorides of $\ce{P, As, Sb}$ show a kink in their stability: $\ce{PCl5}$ melts at 167°C, $\ce{AsCl5}$ decomposes at $-50\mathrm{°C}$, $\ce{SbCl5}$ melts at 4°C (and decomposes at 140°C) [HoWi]
The redox potentials in acidic solution for the (0)/(IV) oxyanions and oxides of chalkogens show a peak at $\ce{Se}$ [HoWi]:


\begin{align}
\ce{SO2} + \ce{4e-} + \ce{4H+} &amp;\leftrightharpoons \ce{S} + \ce{2H2O} \quad &amp;E^0 = +0.50 \ \mathrm{V} \\
\ce{SeO_3^{2-}} + \ce{4e-} + \ce{6H+} &amp;\leftrightharpoons \ce{Se} + \ce{3H2O} \quad &amp;E^0 = +0.74 \ \mathrm{V}\\
\ce{TeO2} + \ce{4e-} + \ce{4H+} &amp;\leftrightharpoons \ce{S} + \ce{2H2O} \quad &amp;E^0 = +0.57 \ \mathrm{V}
\end{align}


the oxidative strength (at both low and high pH) of halogen oxyacids follows the pattern $\ce{BrO4-} &gt; \ce{H_5IO6} &gt; \ce{ClO4-}$. [HoWi]


I think that stability of oxidation states, stability of comparable compounds, and redox potentials of similar compounds are valid examples of d-block contraction. Of course, other chemists may arrive at different conclusions.



Literature:
[Riedel] E Riedel, Anorganische Chemie, Vol. 6, de Gruyter (2004).
[HoWi] AF Holleman, E Wiberg, Lehrbuch der Anorganischen Chemie, Vol. 101, de Gruyter (1995).