I can understand earlier bedtimes if you SAHM but I have always worked and so never actually arrived home until 6.30/6.45 pm with dcs, after picking them up from cm or nursery at 6pm.
So we have always had later bedtimes. But also get up later. Could have not tolerated 5.30/6.30 risers.
And as Maveta says it's a cultural or Northern Europe thing - in Spain dcs stay up later.
But basically do what works for you.
Also as they get older they tend to do activities which can start at 7pm eg brownies,football