The Geometry Dash community keeps pushing the boundaries of what is possible in the game and have been doing so from the start of the game's lifetime. Levels that used to be considered impossible are being beaten almost every day now. But when will levels become so hard that no one can beat anything harder?
First of all, let's get into some history. In the 1.6 update, the level Ice Carbon Diablo X was released and at the time was considered absolutely impossible, no one could even imagine anyone beating it legit. Later, in the 1.9 update, Cataclysm was released and it too was considered impossible, until Riot verified both of them and proved everyone wrong. Today, Cataclysm is considered one of the easiest extreme demons in the game and ICDX is now considered an insane demon. This story repeats itself many times with various levels, most recently, Sakupen Circles— which was also considered impossible in the past, yet Diamond verified it and Cursed became the first victor not long after.
That brings us to today and to the first possible answer to the question. Maybe Sakupen Circles will remain as the top 1 forever and no level will ever pass it. While being a possibility, it is very unlikely as multiple intended top 1s are expected to be verified soon and top players only keep improving.
So, what are some other candidates for the last top 1? We will start with one of the most obvious options, Abyss of Darkness. AoD is a relatively old level by Exen, that he claimed to have verified himself in 2018. He was later exposed for hacking it and the level was forgotten. Later, a player named Dils Thik started to get good progress on the level and eventually even died to 98% (twice!). But then, unfortunately, he had to drop the level due to real life reasons. Since then, people have been making progress on the level but no one could get as close as Dils Thik did.
With this, is AoD the hardest level that will ever be verified? While it would probably be top 1 if anyone verifies it, I doubt it would be the last one.
There are other levels that compete for the title, such as Acheron by Riot (currently being verified by Wolvez), Death Corridor by KaotikJumper (that will hopefully be verified by KugelBlitz), Silent Circles (the possible version by Zynvire) to be verified by Xanii, or maybe Limbo— the amazing memory demon by Mindcap and others being verified by BGram. All of these levels have the potential to be top 1 but are any of them the limit?
When thinking about the limit of human skill, one level always comes up, Silent Clubstep by Sailent, one of the most famous impossible levels in the game, a level made so long ago and considered to be the hardest thing that could be made in GD, has recently started to get attention back with people making progress on this legendary level. A redecorated version has been made by Realvet and more and it looks like if the level is verified it will get rated and placed on the list. Currently, the best run on Silent Clubstep is 14-100% by the player Vision.
Will Silent Clubstep be the last top 1? Out of all the levels mentioned here, this is the level that has the best chance to be the last top 1. But we can't know for sure. I'm sorry we have to end this at an "I don't know," but like we have seen in the past, people beat levels that were seemingly impossible, so who knows what people will beat in the future. So, good luck to all top players and good luck to all the players that are on their way to the top. Maybe you will be the one to make history.