The suit has been in retreat for a very long time, and the period when offices emptied removed the last routine occasion for wearing one.
Predictions of a return have been made repeatedly and have not materialised, and the reasons are structural.
The long decline
Worth establishing because the recent change is a continuation rather than a break.
Formal dress has been simplifying steadily for a century. Hats disappeared, then waistcoats became optional, then ties, then jackets in most workplaces.
Each step was described at the time as a temporary informality and none reversed.
The pattern is consistent: an item required for work becomes optional, then unusual, then a marker of a specific occasion.
What the last few years did
Accelerated the final stage.
An extended period without a daily office removed the habit, and returning to workplaces did not restore it, because the dress code had effectively been suspended and nobody reimposed it.
Industries that had held out — finance and law most visibly — relaxed formally, with several publicly announcing changes.
And the people entering those industries since have never worn one routinely, which removes the transmission of the convention.
Where it survives
Specific and narrowing.
Ceremonial occasions — weddings, funerals, formal events — where the suit functions as a costume for the event rather than as clothing.
Court and certain professional settings with explicit requirements.
Client-facing roles in a small number of sectors where the convention persists.
And as a deliberate stylistic choice, which is a different thing entirely and is worn by people who want to rather than by people who must.
What has not replaced it
The interesting gap.
No single alternative has established itself as the default for occasions requiring some formality.
Which produces genuine uncertainty. Invitations increasingly specify dress in ways that assume knowledge nobody has, and the range of what people actually wear to the same event has widened considerably.
The practical consequence is that the signalling function has weakened. A suit used to indicate a category of occasion; now it indicates that the wearer decided to wear one.
The tailoring trade
The commercial consequence.
Volume tailoring has contracted substantially, with well-known businesses closing and traditional manufacturing centres reducing capacity.
What has survived at the upper end is bespoke and made-to-measure, serving a smaller number of buyers spending more.
And at the lower end, occasion-wear bought cheaply for a single event, frequently poorly fitted, which is the volume replacement for what used to be a considered purchase.
The middle — a reasonably made suit at a moderate price, bought to wear regularly — has largely disappeared, which is the same hollowing that has happened in several clothing categories.
What is actually worth knowing now
Practically, for anybody who owns one or needs one occasionally.
Fit is the entire thing, and a moderately priced suit altered properly looks better than an expensive one that does not fit.
Alterations that matter most are the shoulders, which cannot be easily changed and should therefore fit at purchase, and the trouser length and waist, which are straightforward.
A single dark suit covers nearly every occasion that requires one, which for most people means one purchase rather than a wardrobe.
And separates — a jacket worn with different trousers — cover the middle ground where a full suit is too much, which is where most occasions now sit.
The thing that has genuinely been lost
A settled convention, which had costs and had a benefit.
The benefit was that nobody had to decide. A defined dress code removes a daily judgement and removes the possibility of getting it visibly wrong.
What has replaced it is a continuous low-level assessment of what is appropriate, which is more work and which falls hardest on anybody without the background knowledge to read the signals.
That is a real cost of informality and it is rarely counted, since the people who write about the freedom generally have the confidence that makes it free.
The second-hand tailoring market
An unexpectedly good opportunity created by the decline.
A large quantity of well-made tailoring is available second-hand at very low prices, because demand has collapsed and supply has not.
Much of it is from an era when construction standards at moderate prices were considerably higher than they are now.
The constraint is fit, which is why it is cheap, and which alteration addresses for a fraction of what the garment would cost new.
For anybody who needs a suit occasionally, this is comfortably the best value available and it requires only a willingness to visit a tailor.
What to ask an alterations tailor
Since the alteration is the whole thing and most people do not know what is possible.
Sleeve length, trouser length and waist are straightforward and cheap.
Taking in the jacket body is straightforward. Letting it out depends on how much material was left in the seams, which varies by manufacturer.
Shoulders can be adjusted and it is expensive and rarely worth it, which is why shoulder fit determines whether a garment is worth buying at all.
Asking what can be done before buying, rather than after, is the sequence that saves money.