So when I say dual-purpose, I'm meaning in a role context, rather than a function context. So... shields are single-purpose from a functional perspective, but dual-purpose in that it can be used by, say, combat players as well as non-combat players.
In Elite, essentially, anything a non-combat player could use to defend themselves from PvP can also be used by an aggressor to attack you successfully in relative security. Shields, Weapons, Chaff, Heatsinks, Speed, Agility... it's all available and usable by combat and non-combat pilots.... there's no subtlety to it. A key part here is it's impossible for a non-combat pilot to fit their ship in such a way that forces an combat pilot to compromise their own combat fit, in order to counter that. It's just a glorified "my numbers are bigger than yours" and throw in some twitch reflexes.
Meanwhile in EVE, Combat pilots will invariably fit a combination of Weapons, Armour, (or[1]) Shields, Speed, Agility and EW. But what's a non-combat pilot fit? The main differences are they'll fit PvE enabling equipment and counter-EW equipment.
One example is warp-core stabilisers. I won't go through the mechanics, but combat pilots will usually fit a warp jammer or similar to lock-down a target in order to kill them.
Non-combat pilots will fit warp-core stabilizers which are non-dual-purpose counters to warp jamming effects.
Why are they non-dual-purpose? Because they tank your targeting time hard, so much so your ship could be destroyed before getting a targeting lock... so combat pilots simply can't practically use them as a defence.
But why do Non-com players? Because (activity-dependent) they won't fit guns, as they never intend to shoot... so who cares that you can't lock quickly... you never wanted to shoot anyway.
Combat pilots can counter this with more jammers. But what do jammers come at the sacrifice of? Shields... creating an exploitable vulnerability. This is a common thread for all fittings.
Then there's cloaking systems which are able to be used for very specialised combat vessels and PvE fittings... but are fairly useless for PvP due to a hard-cooldown on targeting. There's ways to counter these too.. but then there's the equivalent of SCO-ready ships, which can exclusively use an advanced cloak with no drawbacks, but they're also not great at combat, yet excellent at PvE.
Speed and agility for combat is usually an Afterburner for +100% speed. But for PvE you can go a microwarpdrive for +500% speed, at the expense of signature radius... but if you're in a chonky hauler, things would be getting wrecking shots already, but it's enough to make speed-based combat ships get wrecked if they use them.
There's definitely awkward/specialised combat fits that might use some of these, but they're memes at most.
Lastly, it's possible to fit a combat ship that carries all the counters to these defence systems and can lock down even the most seasoned PvE pilot. You know what that combat ship is vulnerable to then? Everything. They'll have no defences or weapons to speak of, and a basic transport with a couple missiles or a single escort would wreck it.
There are sufficient of these systems that a thoughtful player can create a fitting and plan their activity to their strengths. And EVE puts PvP as a first-class citizen... which not only means providing the right environment for dynamic PvP, but also giving non-com players the ability to A) defend themselves, and B), still undertake the activity they wanted to do.
There's heaps of things Elite could do in this regard. Unfortunately when it intorduces activities, it does so with no regard for PvP and both how to undertake it, and how to avoid it.
Like, seriously, what's a player in a salvage ship meant to do about a PvP combatant at a titan wreck, except "Be somewhere else" or otherwise go to another wreck? That's not interesting at all.
And most obviously, an AX fit has no place in PvP.
[1] In EVE, dual-tanking is generally a bad idea and doesn't work for most things.
