Depends on the decor.
Paint is easily remedied, wallpaper less so but still not too expensive - and both could be done over a weekend if needed. Tiling would cost thousands and generally isn’t something most people could do themselves either and you have a downstairs that would be very expensive to renovate.
Most people who are paying a million for a family home aren’t going to want to spend thousands on top, and the tiles you have aren’t particularly friendly for families with toddlers who will be learning to walk or still in the rough play stages.