I design build and operate broadcast equipment. A good chunk goes onto UAVs. I've built small quads, and I've played around with equipment fully capable of some of the more complex tasks. E.g. live 3D mapping from an airborne capable computer.

I'm also friends with several people who used to design and build military equipment, including radar systems. Military tech is a weird mix of amazingly high tech, stupidly simple hacks and long lifespan versions of off the shelf technology. I've a fairly good feel for how hard or easy a good chunk of the bits are to build. Most of what I suggested I could personally design and build, or easily commission, given some time, a reasonable budget, and access to restricted resources as required.

In its simplest form, chaff is just tuned lengths of mylar foil. As it flutters, it glitters in a radar beam. This creates a large noise floor. While modern military chaff is more advanced, the old stuff will still cause problems for modern systems. It's not trying to hide a tank, or pull off a missile's lock. It's trying to swamp the signal from a tiny, mostly plastic, drone.

I'm also not saying to reinvent the wheel. Chaff is now a fairly niche defence tool. It's hard to use while advancing, and gives away your position. It also needs to be integrated with other countermeasures to be useful. It is still a fairly solved problem however. It's cheap to make, quick to deploy, and available in bulk, if required.

Most modern military equipment isn't expensive due to its inherent nature. It's expensive because it's a niche product, and the buyers have deep wallets. The same game plays out in broadcasting. A £100k camera isn't that much better than a £5k one. It is better however, and buyers are willing to pay for that difference.

The reverse is also true, as Ukraine is proving. 100 $1k drones are more useful than 1 $100k, ultra capable, drone or missile. The point of a swarm is to allow multiple cheap systems to do the job of a far more expensive weapon.