Shorter, no, but having a private cabin with a shower, and a lounge with a bartender on the plane, not to mention Starlink, would make those 12 hours a lot more bearable vs 12 in an economy seat.
AFAIK: Showers are only available to first class customers flying via the major Gulf carriers. I checked Google flights for business class and first class tickets between Tokyo and London. Business is about 5,000 USD and first class is about 10,000 USD. Assuming that we are talking about first class here (to satisfy your shower requirement), what kind of developer is hacking code at 10,000 meters in first class... except... hmm... Mitchell Hashimoto?
Mitchell Hashimoto's got tres commas in his bank account and his own jet. He doesn't need to take commerical, or even first class. If we backsolve, say $10,000 is a once a month purchase, and $10,000 for a hotel and you stay a month. Say your other living expenses are $10,000/month, so we're shooting for spending $20,000/month. With the recommended shaving off 3% the nest egg, (20,000 * 12) / 3% gets us $8 million in the bank.
So at $8 million in the bank, you could take a $10,000 plane trip, stay for a month, spend $10,000 on a hotel, take a $10,000 flight back. Still upper end of net worth, but nowhere near Mitchell Hashimoto territory.