because they want to
No they do not.
Check on the web.
via Vietnam Airways or Thai Airways either thru ho chiminh or bangkok. If you like to visit Angkor Wat area fly direct from HCM or BKK to REP (SIem Reap) apprx. 2.5 hrs
Yes, you can fly from London to Auckland with a stop in Bangkok. Thai Airlines offers a flight from Heathrow Airport in London to Auckland that does stop in Bangkok. The Bangkok to Auckland leg has a stop in Sydney, Australia. What makes Thai Airlines unique is that, presently, it does not charge any stopover fees aside from departure taxes, and thus this is an inexpensive option for traveling to Auckland.
The airlines that fly to Changi Airport in Singapore are Air China, Air France, Air India, Air Japan, Air Mauritius, Air Niugini, AirAsia Berhad, Airphil Express, Asiana Airlines, and Bangkok Airways.
The shortest flying trip would be around 15 hours with Qantas Airlines if you connect in Sydney .
It really depends on which airline you fly. BA & Qantas fly via Singapore, China Southern fly via Guangzhou, Malaysia Airlines fly via Kuala Lumpur, American Airlines fly via LA, Emirates fly via Dubai, Thai Airways fly via Bangkok, Virgin Atlantic fly via Hong Kong. There are as many options for a stopover as there are airlines.
It can be 11 hours direct. I fly to Bangkok regularly from Manchester, but what I do is fly Emirates airlines to Dubai, have a 2 hour layover and then fly to Bangkok. It literally splits the trip into two equal portions and gives you a chance to relax and stretch your legs ( AND SHOP) in Dubai Airport.
How long does It take to fly from the UK to Bangkok
How long does it take to fly from Bangkok to Athens?
Guangzhou (CAN) to Bangkok (BKK) 2hr 45min to 3hr 00min by a nonstop flight operated by China Southern Airlines or Ethiopian Airlines.
what airlines fly into Bishkek, Kyrgyzstan? Turkish Airlines for example does.