We do thank each other a lot, but not for every little thing.
I think it's because we've both had past relationships where we've done a lot (all) of the chores and it's not been appreciated at all. We really do appreciate and are happy that we are in a relationship now where we look after each other and it's reciprocal. It's lovely to spend an hour cooking dinner and have the other person say 'that was delicious! Thank you', or to spend a couple of hours cleaning the flat and have the other person say 'Wow it looks great in here, thanks!' It shows appreciation.