To be fair to Samsung (and iFixit) most modern handsets from most manufacturers don’t use screws anymore to assemble devices – it’s a case of hot melt glue and more integration into less components. In reality all you can expect is to be able to replace a broken glass and battery. The rest of the components should be built to last the serviceable life of the phone – several years.
In the pursuit of waterproofing this phone uses hot melt glue to adhere the glass back to the chassis. It is removable with effort and a very gentle touch as are all the internals - motherboard, camera, battery etc.
I won’t spoil iFixit’s commentary – the reviewer has a dry sense of humour – but suffice to say that while repairable it is not really designed accordingly. iFixit found:
Many components are modular and can be replaced independently.
The battery can be removed without first ousting the motherboard—but tough adhesive and a glued-on rear panel make replacement more difficult than necessary.
The OLED display needs to be removed (and likely destroyed) if you want to replace the USB port.
Front and back glass make for double the crack-ability, and strong adhesive on the rear glass makes it very difficult to gain entry into the device.
Replacing the Gorilla glass 4 without destroying the OLED is now probably impossible (but Gorilla Glass 4 is the toughest known).