What disadvantages might people have if they have flexible work patterns?

One clear disadvantage is that flexible work can blur the line between personal and professional life. When there's no fixed schedule, it's easy to end up working late or checking emails during family time. For example, as a UI Designer in Shanghai, I sometimes find myself tweaking designs late into the evening because there's no strict deadline. That flexibility can feel convenient at first, but it often leads to burnout over time. At the same time, it can be harder to collaborate with colleagues when everyone has different working hours. Coordination becomes a challenge, especially in team projects where timing matters. So, while flexibility offers freedom, it also requires strong self-discipline to maintain balance.