It's also nice to spend time with the colleagues. Especially as we're only in the office one or two days a week now. I like it, though we don't spend 90 minutes but one hour. We always go to a restaurant off-site and have a 3 course meal with a beer for who wants it.

PS I'm in Spain not France but similar culture. But here you can eat at the desk if you really want to.

Also I go to France regularly and people do eat at their desks there. Some people just like to or they're forced to because of cross-timezone meetings. Like most of these protectionist laws (like not being allowed to email out of work hours) they're only for show and not actually enforced. France is a bit weird like that.