De-syncing is a whole other issue. So think of it like this, everything we see online is basically the server communicating with our client. So say i jump, my client sends it to the server and the server updates and sends this out to other players who can see me jumping. 12 ticks means PUBG puts out 12 updates a second. The industry standard is 60 Tick for FPS games.

De-syncing is another issue and before we even discuss raising server tick rates it needs to be fixed. Usually de-syncing occurs when their is packet loss, In PUBG every players action is sent to the server and the server needs to update. Sometimes this doesn't happen and what appears on your player client is not the same as the true state of the server and this is basically desyncing.

Once De-syncing is fixed then what Faster Tick does is it makes what you see on your client state closer to what the true state of the server is since it's being sent updates more frequently. As an example in Overwatch which is a very fast paced shooter when it first launched they had 30 tick servers. So people would sometimes show that they got hit by certain abilities when on their screen they dodged. With higher tickrates this is less likely to happen because what you see on your client is closer to the actual state of the server. Later on they upgraded to 60 Tick servers.

TLDR: To put it simply Tick is how often the server updates. It isn't the solution to de-syncs because with De-syncing it's the server failing to receive or send updates from the client in the first place.