I actively started changing my habits a few years ago, meaning I changed my diet to high-fibre+high-protein+high-(good)fat+low-carbs, stopped drinking alcohol cold turkey, get up earlier (~5am) before work to work out and go to sleep earlier (~10pm). This has worked wonders for me, I'm always energised and never drowsy during the day, sleep like a rock and needless to say am much healthier overall.
People think of me as a morning person now, which is probably right although it's weird after having lived like an owl for years. I believe for most people this boils down to habit and changing those is hard. An owl-ish life might not be bad for everybody but from my experience it's very taxing on health and social life and the mental state.
In my case having a regular job and kids certainly gave incentive (aka left not many options) to transform into a lark, but most people can probably do it - if they really want to.