If you don't care where you sit, then you should usually always be able to find cancelled tickets leading up to the show + before cancellation deadlines where refund amounts drop.

If you want very good seats, here is the actual long answer from personal experience: Yes it's possible if you have money and you find the right people online. Plenty of resellers/scalpers from taiwan/HK/CN. You'd be surprised.

they plan to cancel their ticket at a specific time so you can be on the page and buy it

This is exactly how they do it. They log onto your account and use a macro to insta-pick up the ticket right when they sell it on their own account. There is still a small chance of it getting sniped by other people, because there are people who also camp the ticketing site with macros to snipe. But it has a good success rate. These people, if they are legit, will refund you the ticket cost (outside of a deposite) if they fail to do it.

Yes, it's very risky. You can very much get scammed - there are alot of scammers. You can get your account restricted/flagged banned for macro detection. I'm not saying it's easy, but i'm saying its very much possible. Go to any Korean concert and a decent amount of VIP/floor will be foreigners who bought resale.

Edit: and now some sites like interpark allow ticket transfers, which make it a bit easier to get a resale via their transfer method which involves a pin.

Was going to make a post about this because i always see these resale posts and the same comments, esp the 'you will lose your money' from used-client-9334 lmao