I had a mixed experience in Decathlon. Went in with a friend and her daughter, to buy the daughter a bike to use around campus. Delightfully, she fell in love with the
cheapest of the city bikes. But then we spoke to the assistant. He told her it was not suitable for daily use. Had a look on their website, and to differentiate between the different models, the cheapest was for "occasional use" and then the more expensive were for regular use.
Nearly cost them the sale, because that was the bike she wanted. Anyway, I reviewed the components, looked at the frame (she's not heavy) and decided he was wrong. I now see they have changed the recommendation to "occasional use or regular short journeys around town" which is perfect. It's survived a year so far, being stored outside, and she still loves it.