The trouble with set homework is that some children enjoy doing it, yes really, and others hate it. A 20 minute task will take some less than 10 minutes to complete whereas others will still be struggling miserably an hour later. It sounds like most GNs here have the sense to realise when enough is enough, and when to allow the child to go and play.
However, I don't think all homework should be dismissed as pointless - and even drawing a picture of a chair next to the French "la chaise" is designed for the pupil to visually associate the object with the word, (multi-sensory skills). Just like learning 20 spellings a week will help the child in writing activities, and the benefits of practising addition/subtraction are great at an early age. It all needs to be put into practice. I hate to hear Anya that teachers don't praise children for the homework they have completed - where are the reward stickers and certificates? Children need to feel proud of their work outside the classroom. Parents/grandparents can have fun too sitting alongside the child and supporting their learning, and even trying different ways to explain things.
The English are very child-centred, and sometimes over generous in the amount of free time they give their children.The school day is pretty short, 9am-3.15pm, 21 teaching hours per week. Compare this with say, for example, the French school day 8.30am-4.30 pm, 28 teaching hours, and it is evident English children are getting off lightly - especially as French children than do an hour's homework on top! Somewhere along the line there has to be some compulsory time for homework, even for younger children in order to install self-discipline later on.