You have to take into account that the Z-Axis are considered tiles that affect the viewing distance.
Best way to see this is the build up a tower of goza mats. Another way to explain it is that, you cannot place something a tile infront of you, if where it would land is 50+ tiles below and above you. The higher you increase your Z-Axis, the less of the surroundings you will see that are at lower Z-Axis...
Also the resolution changes created an issue that that has yet to be, and more than likely never will be addressed with the classic client, which is that the classic client now has much more data to parse to and from the server as not only does the classic client technically have to send data about the increase of terrain, items, players, etc it sees, but it also has to accept more data from the server about what others can also see that that they can accurately be drawn on our clients as well. The servers with the previous allowed viewable distances were optimized around the classic client being able to function smoothly and thus where they were previously was the drawing range min/max for the client to not get bogged down. Bleak did not take the into consideration however when updating the viewing distances. And yes people have always been able to increase their resolutions however your client was actually only able to draw/see so far as allowed by the server.
I've been saying it for years now, the classic client needs to be better able to parse data. It doesn't need new art, resolutions, or any of that garbage... What it needs is to not get bogged down just because it's attempting to draw four in-flight afk gargoyles.