Lever action rifles? A number of reasons:

• Action strength

• Ammunition constraints

• Operation difficulties

• Time needed to load

The lever action locks the breach at the rear, here's an example from the Henry Rifle

This is much less strong than the locking lugs of the Mauser action which you can see, compared to the Enfield, the fastest firing automatic has lugs in the front up in the receiver-barrel area - the most reinforced part of the gun.

This means you can use higher pressure ammo which has longer range, flatter trajectory and better ballistics.

Secondly, the bullets in a lever action rifle are stacked horizontally in a tube magazine - so the bullet tip is resting on the primer of the next bullet in a pattern like this The recoil of the rifle would risk blowing the magazine up.

Thirdly, it's harder to keep your aim and operate a lever action from prone, compared to a bolt action.

Fourthly, a Mauser, Enfield, Mannlicher and many other guns used in WWI could be loaded from either stripper clips or en-bloc Compared to a tube mag gun where you have to load each. bullet. individually. all the while a machine gun is ripping belts of bullets to get at you and the enemy with Mausers, Mannlichers or Enfields has you pinned down.

For the record, slide action guns aren't much better. The bolt tilts into the receiver, and that's not strong enough to use with high pressure rifle rounds. and you still have the same issue with the tubular magazine. You may be asking why not use round-nosed bullets, but spitzers are much more effective when in FMJ form since you can't use expanding or poisoned bullets in war.

Bolt actions, when it comes to repeating rifles, have the best compromise of reliability, ease of use, action strength, and weight compared to slide or lever action rifles.