Filtering anything at all starts to get tricky, even with what might seem obvious. Say you wanted to filter pornography. Does that include sex education? What about certain objective medical information and statistics? Are there specific points where you can draw a line? What about feet, or furries? It's all nuanced and, frankly, not worth the trouble.
Don't click on things you don't want to. I know nobody sympathizes with the difficulties I face when trying to find incredibly obscure infirmation in a see of detritus duckduckgo decided was "close enough" to count. Put in the effort.