They're completely different niches. Blow molding helps you make a million of a thing, 3D printing helps you make a million different things. There's great for low volume items without significant strength requirements. That includes prototypes but also anything niche - like parts for blow molding machines.
replyAnother comment mentioned you can CNC a blow mold. That's completely true and I'm not versed in it enough to know when you'd prefer subtractive or additive rapid prototyping. A 3D printer is a bit more flexible in the shapes it can make but it can only make them out of plastic, which is a huge tradeoff.
replyIs it? With a 3d printer you can print any piece on demand, change design without changing tooling and make pieces that are semi-hollow inside for lightness.
replyEdit - should add, early in the war Ukraine was crowd-sourcing drone parts from citizens with 3D printers at home. This likely grew from that.
This isnt endurance contest, interceptor drones are half battery half explosive with miniscule weight taken by motors electronics and packaging. We are talking 10KW power draw for around a minute.
replyYou can rapid manufacture moulds too, cnc alu is good for 1K shots easily.