To put this in perspective, 250 Gt at the start of 2023 means each of the 8 billion persons on the planet get a 2.6 t/year budget if we collectively reach net zero in 2035, and a 1.16 t/year budget for 2050.
Moreover, to be fair to underdeveloped countries, it would make sense for them to have a larger allowance of this budget given that they are the farthest from having the infrastructure needed to get rid of fossil fuels while ensuring quality of life.
Considering population is still growing, that the current global average (per the article data) is around 5 t/year/person, and that this average is also still growing, we can all see that's not happening.
More on this line of thought: https://medium.com/@bumblebeeunbarred/is-britain-doing-its-bit-for-climate-58f9c78074eb