Though some make it quite difficult to get in to replace the drive, and put everything back together after.

Some are very easy: an obvious compartment at the bottom, unscrew lid, remove drive, put in replacement, power up and transfer old content, done. I've seen both NVMe and 2.5" SATA drives arranged this way. On the other hand, upgrading my friend's laptop recently involved taking most of it apart, the drive was under the keyboard inaccessible from the back, with other link cables (for keyboard, antenna, screen) in the way so they had to be disconnected and were in very inconvenient arrangements for reconnecting after…