What the OP fails to address is whether anyone ever kept these halachos. Just because something is written in shulchan aruch as halacha and we don’t keep it doesn’t mean that we are doing less than previous generations.
Additionally, it’s easy to imagine that all of the answers are written in black and white in the Shulchan Aruch or on the OU website, but that is simply not true. Taking Popa’s example of bugs – we have the term ‘Nira l’einayim’ (apparently – I didn’t look into the halacha) but what does that mean? Does it mean with a magnifying glass? With a microscope? Okay, it’s become accepted that it refers to the naked eye. But does it refer to the naked eye when nobody ever used a microscope to figure out what to look for with the naked eye, or must you examine with a microscope or magnifying glass and then re-check to see if you can see the now-identified creature with the naked eye?
Furthermore, does it refer to creatures that are visible to the naked eye after someone happened to notice it while sitting near a luncheon with a magnifying glass, or does it even refer to bugs visible to the trained naked eye in an age when there is a cadre who sit all day with magnifying glasses hoping to find visible bugs in things so they can “save the public from an issur d’oraysoh?”