I used to work a lot when I got my first "dream" job. Engagement and passion to learn and fear and anxiety of being fired after were the strongest motivators. They pushed me to work hard and sometimes overwork. I was still in university but had time for both studying, working. That was the most efficient and productive period in my life. When you have a single goal, which is learning, it's easy to be focused and consistent in achieving it.
When I felt confident I started to work less and become less focused. There was no need for overworking. Finding time for hobbies and entertainment became easier or at least possible. Together with that, focus disappeared. When you've already achieved something, your attention gets scattered and motivation decays. Yes, I had more free time, but I'm now not sure that's what I wanted and what reflects my mindset.
After some time and progress at my job, I got to lead a small team. New responsibilities appeared. I had to learn new skills and adapt to the new environment. The work became fun and exciting again. Motivation got boost and I focused on learning. Work-life balance suffered but I felt that it was what I wanted. Joy brings happiness. Focus brings joy, or at least let you ignore anything that upsets you.
I noticed that a bad work-life balance with good focus changing to a good work-life balance with bad focus. This cycle follows me my whole life, not only in work but in any projects I pursue. I can be focused and consistent only if I feel passionate about a project. If I don't want to stop or even make a small break, it's a sign of high productivity. I don't know whether it's a good or bad thing, but because it's what works for me, I'm trying to stick with it.