I really don't think most software engineers are flying business class. Any significant distance that would merit it, is SERIOUS money. Even for someone making six figures.
All the companies I've worked for have had travel policies where more than N hours airborne meant an automatic upgrade. I don't know how normal it is, but it's not crazy.
Not normal. A typical bay to Asia business class ticket I see is $6k+. At most conferences small talk is around your travel there and everyone else I've talked to from US companies that was a software engineer was lucky to get a bump to economy plus.
That's fine, and the company I work for has a similar policy, it actually used to be based on just how long a single flight is. Today, you'll get that if you're an executive with serious flight time. With that said, OP did not mention a company shelling out for this, only that the were a software engineer. Which is nonsense.
For domestic travel within the US, first class -- especially booked well in advance -- is often surprisingly cheap, and cheap buy-ups are routinely offered, too (for example, I'm looking at a round-trip for about four months from now for a conference I'll attend, and I'm seeing first class offered for about $250 round-trip).
International business class is expensive, yes, typically on the order of $8,000 to $10,000 for a round-trip ticket. But international is the only place airlines can get away with charging that kind of fare and have people pay it, so that's what they'll continue to do. And when compared to other things people in software-developer income brackets often spend money on, even that isn't particularly gigantic; it's just all in one go instead of spread out over many small purchases the way, say, use of Uber and Lyft would be.
I have a friend who works for Apple and they get dirt cheap business class tickets to China. He says usually around $3000. For a human who has to pay human prices (eg, not a corporate deal), the multiple from coach is much greater.
For the purposes of this comment I just Google searched "SFO to Shanghai". The default is Jan 21-Feb 3 (so you're not paying a last-minute-booking penalty).
The prices are insanely cheap somehow, but the multiple holds up.
$527 economy
$1999 premium economy
$2853 business
$5340 first
I would fly premium economy every time if it existed on most airlines and the multiple was 'only' 50%. What normal human can afford 4x the price for a couple more inches of elbow and legroom? It's far greater than the cost of the actual space.
I tend to assume business will be three times the cost of economy; I suspect SFO to Shanghai is a weird route from a price perspective, much like London to NYC; very few landing spots available. I'd also consider Jan 21-Feb 3 to be pretty last minute.
AMS-IAD (two airports with good capacity) for the default Google Flight dates show 45k for economy, 99k for PE, and 120k (all INR) for business, all on reasonable airlines
The difference between business and economy plus is an order or magnitude, at the very least. My statement stands, just because someone is a software engineer, absolutely does not mean they are spending $9000 to fly to Japan business class. 6% of their salary on a single flight is just crazy talk.