Light drones and big expensive aircraft will both exist in the future and play separate roles. They also won't interact much, aside from a fighter group spearheading a drone group. A drone swarm is too diffuse to be a worthwhile target for a fighter's weapons, but a fighter is too fast to be engaged by a drone swarm.
Air battles of the future will likely be conceptually similar to air battles today, but with light drones replacing bombers with guided bombs. An initial wave of fighters will contest air superiority. If they achieve it they will use it to launch long-range attacks to disable a small number of anti-drone hard points. Once the way is clear a wave of smaller, slower drones can swarm in and bomb a large number of targets with precision.
Dogfights no longer occur anyway. What matters is early detection.
For a drone (even a swarm of them) to compete with a modern jet fighter, it'll need a reasonably powerful engine and sufficient fuel to keep it up in the air long enough to: seek out and engage the enemy, carry a decent payload, and reach a suitable altitude. That all sounds like a lot of fuel and engine power to me, especially if you're expecting this drone (swarm) to operate outside of the immediate vicinity of the launching area.
I see more potential for drones to act as 'screen' for jet fighters once stealth technology is made irrelevant by advances in radar. I foresee the use of, low cost vehicles that resemble fighters (in the ways that count), but carry minimal ordinance (if any) to keep the costs down. They could also provide auxiliary functionality like electronic warfare and scouting.
I mean you could in theory develop a drone that exploded on impact and operated within a limited area, but you've just re-invented the guided missile, with a little extra smarts.
Use the Sidewinder missiles as an example. You're going to run out of munitions very quickly and be left with far poorer capabilities.
Maybe it could be done defensively over territory you controlled, but the 'drone swarm' in this instance really does just sound like a ground-to-air missile.
The smaller your drone the lower its effective range or loitering time. Therefore a transport vehicle such as a jet has to bring the smaller weapon into effective range. The transport vehicle usually also has much better sensors so that it can effectively search for targets. Guided weapons receive additional targeting data from the transport vehicle even after they have been deployed and are heading toward the target.
When people talk about medium sized "kamikaze drones" that are carrying enough fuel to reach a given far off destination they don't realize that these already exist and are called cruise missiles and tomahawk missiles in particular are quite cheap. For the cost of a F-35 the US can buy 100 tomahawk missiles. I still remember that attack where 60 cruise missiles were launched from a single navy vessel at a military airport in Syria with essentially no risk of counterattack.
Most drones are cheap civilian toys. Military drones have had much greater endurance for decades.
> Therefore a transport vehicle such as a jet has to bring the smaller weapon into effective range.
If you are using short-endurancd drones for some reason (e.g., missiles), the carrier can just be a long-endurance drone.
> When people talk about medium sized "kamikaze drones" that are carrying enough fuel to reach a given far off destination they don't realize that these already exist and are called cruise missiles and tomahawk missiles in particular are quite cheap.
That they already exist and are cheap and effective is proof of the point, not an argument against it.
Maybe that's true of regional militaries.
The US wants to be able to project power - often quite far from bases. The drones you're talking about just don't have much of a range.
I'm not saying they won't be used - I'm sure they will be. But there will also be much larger and more expensive drones as well.
This exists already. Those "drones" are more commonly called surface-to-air missiles.
The limited factor is targeting: as has been well publicized, modern aircraft have been engineered with stealth in mind, which means they need to be quite close to radars before they can be detected.
The solution, which was discovered in Yugoslavia, is to use low frequency radar to detect the stealth aircraft, and wait until they get close enough (defense in depth is necessary here!) before turning on your target grade radar at the last moment.
As you might imagine, this is a difficult and dangerous process, and so has only been successfully accomplished once.