But @Branka-and-Silvia0 (can't seem to tag you), I have also had wonderful, relaxed happy people who left glowing reviews, 5 stars in every category, no negative feedback whatsoever, and still 4 stars overall.
The problem is that for many people 4 stars is a very good rating. The poor guests have no idea the damage they do when they leave you 4.
Either Airbnb needs to properly educate the guests about this (they say they will, but still no evidence of it so far), or stop this silly penalisation for 4 star reviews, which would be more realistic. Penalise for 3 stars and below. Full stop.