Personally IMO if the pixellation filter makes the graphics resemble pixel art it'd be great as pixel graphics is more a style than anything, but if the source graphics are more realistic, or are 3-D rendered (be it pre-rendered or real-time) this does not work so well. Here the result looked like PS1-era (or DKC on Super Famicom) graphics, which IMO, might look impressive at their time, don't age well and look ugly nowadays, unless it's intentional to mimic that PS1 era quality.
On the other hand, if the filter is more extreme, like apart from lowering the resolution, lower also the colour count, such as posterising the screen it may work as a style even though they look even more ugly, as there are indeed games intentionally designed to use such kind of presentation.