It's going to be both, and it's because of physics.
At this moment, the best way to put kinetic energy into an enemy is sticking some quantity of explosive on them.
You have a few ways of going about this. Two we consider today: 1) a chemical charge launches a block of explosive ballistically at a closing range of mach 2-5, 2) a complex assembly of plastic/rare earths/silicon/PCBAs flies over to the enemy at somewhere around "fast bicycle" or "leisurely highway" speeds.
By weight, 1 is cheaper, and all you lose is the explosive. 2 is more accurate, but that whole flying assembly is a loss.
Now, when you do something cute like take one little chunk of electronics and stick it on your block of explosive, and then orbit your doodad at a nice safe distance so it beams a homing dot on the target - your ballistic explosive sees the dot and steers toward it. See what I'm getting at? Cheap as 1, accurate as 2.
This is a really, really winning combo when you can pull it off, but lately, UAS ops has gotten a universe more difficult with the dirty dirty EW and now with all sorts of countermeasures.
Even better reason for our little flying widgets to keep their frickin' distance. Even if they get swatted down, they can cue in shot after shot after shot, with much more bang.
Traditionally artillery shells (155mm as discussed in the article) have a maximum effective range of 30km. That means that the artillery vehicle can only function within 30km of the front line.
Drones have dramatically changed this equation. The current drone "kill zone", which used to be several km from the front line, is now 15-25km deep, and Ukraine is pushing this to 50-100km. That means artillery cannot operate without being targeted by FPV drones. It is also becoming logistically difficult to supply the large number of artillery shells needed without getting struck.
Once the kill-zone reaches 30km, which it will by 2027, artillery will be completely useless.
But artillery only has a short range, less than 50-60km. Ukraina is bombing trucks with FPV drones at that range now.
So you'd need serious anti-drone capabilities to get the artillery close enough, and good luck if you have it sitting around deployed for any lenghth of time.
Modern artillery doesn't sit in fixed emplacements. It fires a few shells, and then moves. For example: https://en.wikipedia.org/wiki/Archer_artillery_system
Sure, but when they're moving they're not shooting, so those few shells better count.
Both shooting and moving is very detrimental to staying hidden. And with FPV drones moving doesn't do you much good unless you move out of drone range, which as mentioned is or very nearly is 2x the effective range of such artillery systems.
The attack drones don't have to be big, just big enough to score a mobility kill and the artillery is pretty much f'd in the a...