I don't think you can completely separate indoor from outdoor air quality issues. I say this because I am quite concerned about the air quality in my house and have windows open throughout the day, winter and summer.
However, particularly later in the day we have noxious fumes entering the house from our neighbours' wood burning stoves - the fumes will enter even through closed windows. Thus opening the kitchen and other windows in the evening whilst cooking, for example, just results in a different source of toxins in the house. in the summer, we have the issue of bonfires.
IMO, these are far greater sources of PM2.5 and VOC than anything within a well ventilated house. (though I think, increasingly, houses are not well ventilated, on the excuse of energy efficiency).
I firmly believe wood burning should be banned. It is polluting and unnecessary, except for those off grid.
I do not use air purifiers, as they are often noisy, expensive and I am not certain of their efficacy.
I am not concerned about particular indoor pollutants. I am aware of the dangers of, eg bleach, limonene, etc. but as I have stated, I believe good ventilation is the key.
I think principally the homeowner should take responsibility for the air quality in the house but I also think that builders should make sure the structure has good built in ventilation.
IMO the obsession with energy efficiency has often resulted in houses and flats without proper ventilation - and by this I mean fresh air, not recirculated air conditioned air - often everything is airtight, windows, doors, not a draught anywhere, resulting in an overheated fug.
And yes, more education is needed - open windows and don't overheat your house!