They have the same data, you just linked to older versions of the UN data:
> This visualization presents a big overview of the global demographic transition, based on estimates from the 2019 data release from the UN Population Division; other charts use the more recent 2022 revision, which projects slower growth than previously expected.
> This visualization presents a big overview of the global demographic transition, based on estimates from the 2019 data release from the UN Population Division; other charts use the more recent 2022 revision, which projects slower growth than previously expected.
https://ourworldindata.org/future-population-growth#global-p...