It depends on what characteristics you evaluate when speaking of relevance.
Tech-wise it was irrelevant and dates even for 2016 and 2017 and no one will convince me otherwise. BMWs, for example, had LEDs, HUDs, 360 cameras, and other stuff in the F generation of their cars. Giulia still doesn't have it. Giulia's tech is the 00s, not late 10s, let alone 20s. Do you know that there are trims of Giulia with halogen lights?
There's a huge hairy BUT. Engineering wise in my opinion Giulia is a perfection in this segment, is relevant, and will be relevant for many years. I test drove BMW F80, F30, G30, Audi A4, A5, V6 Stinger, Standard Tesla 3 and nothing compares to Giulia, they're all good cars, some very good, but it doesn't amaze you, doesn't feel special, you don't question yourself how did they do that? And if you think about it, the progress in engineering is not that rapid, I can see many car brands just doing minor upgrades to their engines, transmissions, and suspension but overall it's the same old stuff used in the 00s or even 90s. And then they stuff cheap 90$ monitors and interior lights from NFS Underground and it attracts the general public. The interior tech impresses you for a day or a week and then you're stuck with a car driving like crap. But here's a trick - a non-car person would not notice the majority of the driving issues and won't care.
Tech and brochures with blingy bullet points buy cars, and engineering like in Giulia makes you keep the car, makes you a fan or at least a brand supporter. Same with BMWs, people buy them because of the brand or just overall brand perception of luxury and sportiness, but then buy BMWs again because for example there's no better drivetrain than the B57 or B58, because of engineering, not because of the 360 camera. The majority of people whom I know and own a BMW, they're BMW fanboys. Same with Alfas.
The difference of Giulia though is that on paper it doesn't impress you with gazillion bullet points describing all the features like laser lights, HUDs, automatic parking, electric trunk lids, and so on.
Only car enthusiasts would care about bullet points listing LDS, aluminum paddle shifters, Brembo brakes as standard, 50-50 weight, carbon driveshaft, double wishbone, 5 link suspension, and so on. The general public doesn't even know what it is for. But the BMW will offer almost the same, but much more flexibility in specs + a lot of blingy tech stuff for everyday use. A non-car person can go to the BMW dealership and spec a 320D wagon with laser lights, HUD, and other stuff and car enthusiasts can spec an M340i with manual seats and no HUD if they want to keep the price lower. Or an M340i/M340D wagon!
And I don't know about the US, but here in Europe average NET salary in the mid-class could be say, 2-3-4-5 thousand euros monthly. Veloce (Ti Sport) costs around 60k, Veloce Ti (Ti Sport with carbon and perf. pack. or Estrema nowadays) would cost closer to 70k euros. Now compare it to the average salary. Then think of 2euros for 1 liter 98 gasoline prices = 7.5 euros or 8.15 USD for a gallon. I spend 300 euros on petrol alone per month. Where I am leading to?
You'd be paying 700 euros for leasing and 300 for petrol + maintenance and taxes in some countries. This is a very pricy car to own in Europe. 1/4 of 1/3 of your income. It's a privilege, not just some car.
For that type of spending, you have to either be a die-hard car enthusiast and you just don't care, or it should be doing EVERYTHING as a car.
That's why if a person over here can afford a 60-70k car, they'd go for something that offers both tech and engineering and probably cargo space and is fairly fuel-efficient. It should tick as many boxes as possible.
And that makes Giulia a very niche car a prior. You will go and rather buy a well-specced Audi Q5, Macan 2.0, X3, XC60, or some station wagon/liftback or two Qashqais if you're a family man and need 2 cars for 70k
And you won't see a lot of Audi A4, A5, BMW 3, C classes in Europe actually, because they don't make a lot of sense anymore for the average person. They're already quite pricy, but the use case is narrow. If you can afford just 1 car, it's not very practical. Want comfort? Go for BMW 5 or A6 already. Want utility? Go for an SUV. Compact premium sedans are a niche thing on their own already, let alone Giulia.
Stelvio failed because it doesn't make sense, apologies to everyone. It tries to be sporty, compared to other SUVs it is, but in general, it's not. It's a huge compromise, but then it also loses in other departments that are important to the general public. Keep the brilliant looks of Stelvio, make it slightly less sporty and more comfortable ride, improve the interior just a bit, add some fancy tech options and then it'll become a well-sold SUV.
TL/DR
I think you can't and couldn't make anything to make Giulia a sales hit, maybe just boost sales a tad.