I don't think it's CGI - it may be that the smoke didn't show up the way that it's filmed, up high on a hillside somewhere? And long intervals between bursts. Many of the fireworks pay tribute to the Brazilian flag, like these ☟
No indication of when that video was filmed, but these ☟ are current, and lots of smoke!
New Year's 2020: Brazil puts on nearly 15-minute spectacular fireworks show
https://www.youtube.com/watch?...
New Year's fireworks in Brazil
https://www.youtube.com/watch?...
Why would anyone do a CGI video of fireworks anyway ☺
