What’s the deal with square traces on PCBs?

For all the tips and tricks presented to first-time board designers, the ‘acid trap’ explanation is the implicit reason for why you should not use 90-degree traces. ‘Ease of manufacturing’ is the reason for not using 90-degree traces on many articles for the tips and tricks of PCB design. There is no specific reason why every circuit board design should shy away from 90-degree angles on traces, it’s just something that you shouldn’t do because it looks wrong.

Source: hackaday.com