Why Apple is making thinner and thinner devices

Because only they can?

So why is Apple making things thinner, rather than expanding battery life? Why are they sacrificing headphone ports to push their designs into thinner and thinner dimensions?

The answer is that anyone can make bulky tech with massive battery capacity.

But no one can build devices that are as miniaturized as Apple’s.

https://write.danilocampos.com/why-apple-chooses-thin-devices-over-longer-battery-life-35406986a7ac