Big budget movies are generally planned for a release in summer or during a holiday season.
2.0 was initially scheduled for a release in January but as the graphics work had not been completed, the movie was postponed to a summer release and finally it released on November 29, a date which took everyone by surprise.
Baahubali 1 for instance released in July but the makers were more careful and released part 2 in summer according to schedule and reaped a windfall.
2.0 is primarily aimed at family audiences and children. But there are no holidays now and while day 1 saw huge openings, theatres were conspicuous by the absence of children. Even in the US, it’s the same.
With its release timing, 2.0 has downsized its biggest target audience.