On rebuildable vapes, where everything but the electronics are user replaceable, the electronics are the weak point. There also are seals that need replacing and some poor quality atomizers(the vape production part) need replacement from wear. Legitimate batteries(not recycled and relabeled or off-brand) can last for 200-500 charge-discharge cycles.

There are "mechanical" devices that have no electronics, but they are more risky because they create a hard short of the battery and a lack of appropriate caution can lead to catastrophic failure which may result in physical harm or property damage.

The problem is the hassle of making coils and repacking wicks. They do have replaceable wick+coil units that aren't really rebuildable, but it does cut down on waste compared to disposable units.