there is guys use vr headset and get 100000 block reach
Not sure about VR, but about "reach" you gotta know that sometimes its just ping (as much as it may often sound like a cheap way to excuse literally all things that either go wrong or look like hacks).
Not too long ago I reported a guy who, from my perspective appeared to be reach hacking. The report even got accepted. He was unbanned shortly after though, turns out the guy was a youtuber (I only found him because at some point I noticed the clip I used to report him had like 30 views, so I tried to see if anyone may have shared it, he did that).
Here is my perspective:
Here is his:
When you watch it from my perspective, it looks like I am being hit from a really large distance. And not even just because of FOV, you can literally count the blocks on the ground and from my perspective I am being hit from at least 5 blocks away at times. From his its just a simple combo that happens within a normal hitting range.
[On an unrelated note, before you call me an idiot for calling the leap feather a fly hack, I forgot that thing existed, its a rarely used item. The last time I saw anyone use it since the update was literally in this one fight. And I have not seen one since. Also, somehow, that clip was enough to get the guy banned by an actual moderator, not sure if due to reach or flying, but it had to be one of the two.]
You see: the other player, according to his forums account, lives in japan, I live in germany. He probably has like 200-300 ping on average (if not more), Meanwhile I can go below 20 on a good day. A difference in ping so high can lead to effects like that, at least since the update (I have not seen something like that happen this way ever before the update... I've played on this server for the first time back in 2018 for crying out loud).
Up until the update, ping usually just caused you to have weird movement, visibly lag, "teleport" due to lag, and so on. Now it makes anyone with a high click rate look like they got 27 blocks of reach. And according to a few other, rejected, reports I had made on "reach hackers" since the update, it is apparently a completely normal thing...