When it comes to the overall design of on-foot gear (particularly the 3 suits), once you realise that Arx-funded cosmetics like skins or suit packs were what they were designed around first and foremost, everything starts to make a little more sense (from a developer's perspective at least).
The only reason I can think of why we have 3 distinct suits with a "signature tool" as an excuse to set them apart is to spread out visual customisation and spread out and flatten the engineering progression curve.
From a lore/gameplay perspective not being able to wield an arc cutter or plant scanner independent of what suit you're wearing makes little sense (why can't I cut open a panel with a clearly handheld device not connected to my suit, in an Artemis suit for example, or scan a plant in my Maverick).
Nor does the fact you can visually customise your suits with silly add ons that don't affect gameplay, while weapons don't have any visual distinctions in the form of mods that visually represent whatever you fitted to your weapon (silencer, scope, etc.). Something that has been standard staple in games that feature guns for decades now, but is missing in EDO.
I've stopped spending much time on suit engineering and just stick with the pre-engineered stuff you can find in random stations - not that this is particularly engaging gameplay either if you set out to hunt for them, and you'll spend the majority of your time sitting in super cruise, but G2/G3 without mods is all you need to do whatever you want on-foot (incl. High CZs). It's a shame that the game doesn't give you a better incentive to work towards more advanced engineering (like more challenging scenarios where you really need G5 gear with particular equipment) but there you go.
As someone else said though already, the game is what it is, Frontier, instead of shaving off the less appealing edges of engineering features instead doubled down on them. The appeal of Elite is the sandbox/stellar forge, everything else is uninspired, half thought out game design that's tacked on to that as a mere excuse to engage in any of the activities the game offers. And I don't think this will ever change fundamentally.
If you look at the game like a theme park instead (that's after all Frontier's area of expertise) and just jump from one activity to the next once you get bored you'll probably have more fun with it if that works for you.