But what they do is also specify the time it takes to put the ball back into play - 30 secs for a scrum, 1 minute for a penalty, 90 secs for a conversion. Otherwise the clock still runs and of course it keeps running after the clock gets to 80 minutes until the ball goes out of play, so the referee can not suddenly whistle as a ball is played into an attacking area.
If teams fail to keep to time then a free kick is awarded (or kick is disallowed).
The clock stops for substitutions, TMO, injuries or if the referee decides to stop the clock because they need to deal with an incident. So players are not playing for 80 minutes. The various attempts to speed the game up have moved them from 28 minutes ball in play time at the 1987 World Cup to 34 in 2023 (source:
https://www.statsperform.com/resour...istical-analysis-on-how-the-game-has-evolved/) which is still not half the game!
So football could work on a similar basis - and a free kick instead of a booking would certainly speed things up! But as with anything it needs to be consistent. And one way to be consistent is for the official clock to be shown on a screen where possible - or where both benches can see it where it is not (Anfield, OT and lower leagues). It would be good to get to a consistent 60 minutes in play - more if it can be managed.