Level design and speed

 The speed of the level/ gameplay is affected by the factors of the environment for how fast the player travels. The faster the player moves/ more movement tech, the more likely the player is going to be playing defensive with speed rather than offensive.

The lack of any actual challenge to the speed makes it boring on one hand but on the other hand it's still fun just the fact the fun doesn't last that long is the major problem.

The level design often having it where the player doesn't stick around for long in the given map/ area. The game becomes much easier to beat overall. These kind of encounters come with a question of how to solve this; what just make the map bigger?

Well yes and no; the issue is a lack of challenge, a lack of obstacles. It's not an issue of world size, not entirely at least. You can have a character travel fast around a small map but the lack of challenge/ trails for the character to go through is the major issue.

The faster the character, the more challenging terrain to enemies that should exist, you want the player to slow down? Then not only rely on bigger levels, make maps/ areas that force the player to slow down or have a fast reaction time.

Have the enemies blocking doorways, entrances, exits, and etc.

The harder the challenge, the less likely the player is to breeze through it. If you are only relying on a bigger level/ more walls to get in the way then the game won't feel all that challenging and feel big and empty. A large empty world isn't as fun as a closed off/ harder to beat world.

What about linear games?

Have side off paths/ areas the player would have to get to for a reward for making boss fights possible or something akin to that with having it where that upgrade came in clutch. This is what Metroidvania as the such do; have a system where the player is in an environment that creates a difficulty curve for those who explore and those who rush through the game. Those who rush through the game will be punished while those who take time to explore will be rewarded with an easier time.

The challenge should be a tough road ahead, not an easy breeze of a time. You shouldn't punish players (at least not directly) for going too fast; you as the designer need to find ways/ reasons to make the player slowdown or speed up and tackle the tough challenge of going fast while dealing with things.

Minecraft food system

You could always use a food system like Minecraft with having the player get food in their system with them chomping down on the food, regaining stamina, etc. Some form of system where the player needs to take their character's health into consideration is always a good thing. The only crowd not really affected by this are speedrunners but honestly that's not the crowd you need to worry about unless your game is all about speedrunning.

In general think outside of, "oh just make world bigger" and start thinking of clever ways to get the player to slowdown.