Many people talk about Xianyu, and I looked through it. The most I use on Xianyu is still finding scalpers, not just for concerts but for daily meals.

I don't know when it started, but many restaurants that aren't even that impressive have begun to queue up crazily for reservations. Here in Shanghai, from Sushi Lang to Griller, some have hundreds of tables, which is abnormal.
Normally, restaurants in malls also have to wait an hour, and popular spots can have a two-hour wait. On Xianyu, you can basically find a scalper for restaurants under 100 yuan, and most of them have tickets. You can get in within 10-20 minutes.
Queuing is impossible; I absolutely can't accept waiting so long just to eat.
Last time I went to Beijing to queue at Four Seasons Minfu, and someone was very upset, questioning the staff why there are scalper tickets even for offline queues.
Indeed, the scalper teams also arrive early to get numbers, which shows there's still a market, and it's hard to judge people.
I finally came to travel during a holiday, and I can't waste a few hours just to eat.
The supply and demand balance: if you don't want to queue, either come at 4 o'clock to get a number or pay a premium—it's reasonable.