A large display, fast processor/GPU, and wireless are all battery hungry components. These require a large battery to not only supply enough amperage but have enough capacity to last more than a few minutes. Batteries heat up when charging and when discharging. Things that heat up need to expand. The electronic components also heat up with usage further complicating the thermals. Vents and fans are untenable in something held in one hand or put in a pocket. The total envelope of the phone is constrained by human hands and pockets.

The modern "sealed" smartphone design exists because it satisfies those constraints. Non-removable batteries can have much thinner outer packaging than removable ones. They don't need to resist drops and punctures and still get underwriting certification. Glued components don't tend to wiggle themselves loose after years of thermal exercise. Glue with more seamless casings increase water resistance and overall durability. Glue also allows for smaller contact surfaces than are possible with screws giving more volume to internal components.

A phone that is easy to disassemble will be much less durable than one that's sealed. In the common case where internal access is never required, the durable phone will be superior to the easy to disassemble one. User serviceable batteries need thicker more durable envelopes which means lower power density than fixed batteries.

Most consumers do not want the easily repaired phone. It's going to require a lot of performance and ergonomic trade offs over the sealed flagship phones. Even if people went for repairable phones en masse it's not like they would stay out of landfills.

Even if screws over glue halved the effort to replace a broken screen the component cost wouldn't change. So a repair might be a few tens percent cheaper to perform. Even passing the savings on to a customer, it's still likely someone with a broken screen or whatever phone-ending damage would just buy a new phone.

That's not clear. "Larger display" is easy and obvious from a marketing standpoint. But it's not clear that buyers are benefiting from them.

I can, in fact, point to the Galaxy Tab S8 as an example. My wife wanted AMOLED for the display, but that forces the 12.4" display (or bigger) which my wife didn't really want.

Manufacturers like Samsung and Apple are delivering what is convenient for the manufacturers--what the consumer actually wants is a second level consideration.

Apple and Samsung manufacture hundreds of millions of devices per quarter. They have to optimize for the manufacture of devices. They couldn't achieve their production volume without some manufacturing-friendly concessions. It is extremely difficult to manufacture hundreds of millions of complex things.

There's 31.5m seconds in a year. If it took one second to build an iPhone, Apple could only manufacture 31.5m of them. To meet the demand for hundreds of millions in a year Apple needs to build half a dozen per second. So shaving a half second off manufacturing time by using glue instead of screws is not just a consumer durability win but simply enables their production at the necessary rates.

But to suggest that manufacturing needs override consumer demands is just silly. There's no need to produce hundreds of millions of devices without consumer demand. I don't see how you can suggest Apple and Samsung produce only convenient to manufacture phones when both are offering incredibly complex devices. If they were only interested in devices that were convenient to manufacture they'd but the BOM by a third, source only the shittiest quality screens with huge defect rates, and allow the sloppiest fit and finish while still shipping something that didn't immediately fall apart or explode.

Both companies (and many other manufacturers) are shipping tens of millions of extremely high precision manufacture and high complexity devices festooned with gewgaws and features. There's nothing easy about their manufacture. They're selling features first and then figuring out how to manufacture them at scale.