ByteDance's "first comeback" in the large-model arena, 36Kr attributes it to Seedance 2.0. Behind it is a not-very-complex but rarely clearly explained technical judgment — moving the training architecture of video generation from 2D UNet extension to 3D, into a native video pipeline with DiT (Diffusion Transformer) as the base. Early ByteDance's AI Lab's PixelDance took the "image diffusion to video" shortcut: using 2D UNet extended to 3D, structurally faster and more stable, but with the upper bound locked by the image model. At the same time, Kling and Sora had already shifted to DiT, leaving ByteDance about a year behind on video generation. When transitioning from late PixelDance to Seedance, the biggest change was switching the architecture to a DiT base. DiT's benefit is closer to the Scaling Law — as parameters, data volume, and compute continue to grow, the effect continues to climb. Seedance 2.0 pushes parameters to the 200B tier, evaluated by multiple industry insiders as the confluence of the "model is large enough + data is rich enough" two lines. More invisible is the data. Behind every Seedance algorithm sit over a dozen data colleagues, and behind them a thousand-person evaluation team, who use meticulous annotation to accurately match user prompts to training data. Most material is bought from film-grade footage, then decomposed by LLM into scripts and storyboards. ByteDance internally has a "no distillation" consensus on all models — the goal is global SOTA, and they must synthesize and clean their own data. The commercial turning point is even sharper. Among Volcano Engine's MaaS revenue this year, Seedance has already contributed more than half, with 720P video priced at 1 yuan/second with no discount. Seedance 2.5 will be released in late July, and Volcano's goal is very clear — squeeze into global first place after Veo. So when ByteDance pulls Doubao 2.1 onto the Coding/Agent table, the video model side has already run through the closed loop of "good model → good scenarios → high profit". This underestimated business has only just begun.