Points are related to achievement relative to a set scale, not relative to the people your competing against, so that different decathlon events can be compared across different times.
Then you can have personal bests, seasons bests and world or championship records all against the same scale.
10 events in each decathlon, each with a possible score of up to about 1000 for achieving a world class time/height/distance – so a possible potential max score of about 10000. for example, 10.4 sec for the 100m gets 1000. Was watching their pole vault today, and every 10cm more in height was worth 30 points, the winner got about 900points for 5.4m.
The WR is about 9000 points total.