What does one of fashion’s few global household names think about the industry today? “There is too much shouting,” says Giorgio Armani.

He is worth listening to: at 90, he retains sole control of his company, with a fortune estimated by Forbes at $13bn (£10bn).

Armani told the Guardian before a catwalk show in Manhattan that “calm rather than loud” style was the secret of his success. “It’s not just about power dressing; it’s about dressing with character, strength and dignity.”

Armani, who rarely gives interviews, described himself as “not one for fanfare” but he pulled out the stops to celebrate a new Armani boutique, apartments and restaurant in New York.

The designer swapped the navy crew-neck sweater he wears for his shows in Milan for a bow tie and satin-lapel tuxedo, observing the black-tie dress code issued to 650 guests including the actors Brooke Shields, Liev Schreiber, Brie Larson and Orlando Bloom, the singer Lily Allen, fellow designer Michael Kors, and Hillary Clinton’s former chief of staff, Huma Abedin.

The clothes on the catwalk stuck fast to the hand-in-trouser-pocket nonchalance characteristic of Armani. There were slouchy trousers and slender waistcoats, fluid column dresses and soft jackets. Colours were cookie-jar neutrals of warm oatmeal and toasted biscuit, or skyscraper shades of silver and gunmetal. These were clothes that – if you could afford them, which is a big if – you could actually wear.

Armani believes he is in the business of design, not entertainment. “It sometimes feels as though the clothes are of little interest to those who create them,” he says of the vogue for catwalks packed with stunts.

The New York moment was unmistakably a flex for a designer whose age raises questions about the future of his brand. This was the first time a Giorgio Armani show had been staged outside Milan in its 49-year history.

Armani, who made men look sexy in suits and then rewrote the rules of womenswear by borrowing from menswear, said before the show that he saw “a lot of the style revolution that I helped bring about, on the streets of New York. Together with Milan, this is the city that – first and better than any other – understood my idea of snappy, modern, no-frills style that embodies urban living with elegance”.

Not since the last season of Succession has a pop-cultural protagonist faced such a public succession question. Unlike the fictional Logan Roy, Armani has no children. No future plan has been made public, although a strong hint toward continuity was dropped at his Emporio Armani show in Milan last month, where for the first time four members of Armani’s design team joined him for a runway bow, including his niece Silvana, one of several family members in the top tier of the company.

Last weekend, the designer told the Italian newspaper Corriere della Serra that he intended to retire within two to three years. A proud defender of Italian style, Armani has indicated in the past that he does not want his empire to pass into the hands of one of the French luxury conglomerates who now dominate fashion.

Armani will continue without Armani, the designer told the Guardian. “The main design principle I have passed on is this: ensure the garment does not overpower the person but, on the contrary, enhances them. I have also taught my team the art of subtraction, championed by Coco Chanel. Lastly, I emphasise staying connected to reality – never retreat into an ivory tower, but move with the times … Fashion has, in a subtle yet incisive way, rewritten the rules of femininity and masculinity.”

The US has been a power base for Armani since the 1980 film American Gigolo. Richard Gere’s suits, draped over his body rather than boxing it in, made Armani’s unstructured tailoring an overnight hit, and the alliance with Gere was the start of a playbook for celebrity dressing in Hollywood that brands have followed ever since.

Jim Moore, GQ’s creative director at large, told Vogue this week: “Armani taught us how to be elegant Italians, to have that cosmopolitan look no matter where we lived.”