I do not think the requirement for precise movement is an issue,the issue is the game requires the player to move precisely but the player is given a tool(slide) that moves imprecisely.
The spikes are not an issue,the issue is that when the player is hit,the player is knockbacked uncontrollably(which takes control away from the player) into other things like pits,pits and pits which leads to insta death.
I wanna be the guy is a game full of cheapshots(where the game is also designed around it) and the player dies from anything in one hit,but the main difficulty comes from the challenging obstacles,while the player is able to control the character precisely to deal wih them and the game also gives a lot of checkpoints in balance.
Just as examples,but mechanics like coyote jump and player have a hitbox smaller than it seems are traditional game design that makes the player feel the game is fair and fun even if the game is difficult.
In the end the game being fair or not is not important,what is important is making the player feel like the game is playing fairly.