Hello,

on the wiki of command https://community.bistudio.com/wiki/setViewDistance
it's written : "Client-side max view distance is limited by the server's view distance."

But if you join a server, opens debug console and execute :

setViewDistance 99999999;

it will set the view distance the maximum scripted (40.000)
even if in the server difficlty settings you have put for example

viewDistance=4500;
preferredObjectViewDistance=4500;