I don’t doubt there is mould in some properties but if it’s not widespread the householder should get a sponge , a bottle of bleach and a bottle of mould remover , I have a small amount of mould in the bathroom but it’s easily removed , I also read somewhere that a family who are in the news regarding damp and mould never opened the windows to get fresh air in ,the curtains and blinds were completely closed and couldn’t be bothered to attempt to get rid of the mould , family also went home to their native country for three months ,