This question is last Jedi related so let's keep preview spoiler free.
The manoeuvre that vice admiral Holdo (with the purple hair) uses towards the end of the film seems remarkably effective.
It seems that it would have worked pretty well much earlier. Especially as
Two other ships were just allowed to run out of fuel and be destroyed.
It seems doing it earlier with different assets would have incurred less losses. Yet nobody seemed to consider it. Any in universe reason why?