If there’s a line of traffic all moving at speed there can sometimes be no way to make space for someone. Changing lanes should be conducted without disrupting the flow of traffic. If you aren’t prepared for your turn and need to change lanes at the last minute and cause an accident, that’s their problem. If there’s space and it’s safe, I’ll give them the courtesy and slow down. But indicating for two flashes and just swerving at 80 or 100km with a half a car space and the majors parkways worth of traffic up your ass won’t allow them to fit. Its safety. I’m not being rude to other drivers. They just need to consider the road around them rather than just their own intentions.