There is no shortage of fantastic street food on Nanchang Lu near XiangYang lu. Street food stalls sell pancakes, flat bread with meat in, fried dumplings, noodles and even the best bagels in town. However, some people who work in the offices on that junction still order their lunch on their phones and have delivery people stand outside the offices waiting for them to come down to collect it. 
I think just because you can stay at your desk and get your lunch, doesn’t mean you should. This is especially true whn it means adding to the thousands of crazy moped drivers who zip across the city, darting down narrow lanes as short cuts, driving on the pavements, the wrong way along roads… all to get some lazy person their £1 noodles.
In addition to adding to the midday bedlam on the roads, it’s just lazy to order food when there are very good lunch options at the bottom of your offices.
And of course it’s healthy to get out of the office for a break.
That’s what I think anyway. I’m sure there might be good reasons why people can’t be bothered to go downstairs.. can’t think of any off the top of my head though.