What is the issue? You can still download the world files, but it would be inconvenient to store them in Minecraft's unoptimal format.
And the actual size of the 2b2t world is likely much larger than 15TB. The data for this project is stored in a highly compressed form, much more efficient than the game's standard file format.
> a 1,024,000² (1M²) area of the Overworld (Dec 25 2025 - Apr 13 2026), > a 512,000² (512k²) area of the Overworld (Nov 11 2024 - Dec 12 2024), > a 256,000² (256k²) area of the End (Jan 23 2026 - Feb 15 2026), > a 100,000² (100k²) area of the Nether (Jun 9 2025 - Jun 14 2025)
How do they both provide a single snapshot of the world while also providing a date range.