[LiamPowell]

There's simply never a reason for a user to replace a fuse in a properly designed device. If a fuse blows then it means something has gone horribly wrong and replacing the fuse won't fix it.

The exception would be a device that sends mains more-or-less directly to a user device, then a fuse would be protecting against a fault in the user device and should be replaceable. A lamp that takes a regular light bulb would be a good example of this.

[regularfry]

Replacing the fuse alone won't fix it. But it at least gives you a chance to be able to fix whatever the underlying cause actually was.

[LiamPowell]

True, but in that case the fuse only needs to be as easy to replace as whatever else you're replacing. If there's internal socketed components then the fuse only needs to be internal and socketed. If everything is soldered to a board then it's fine to have the fuse soldered too.

Many older appliances did expect the user to put some external bits in that would be across mains, or maybe across a transformer to mains, and in that case the fuse was just as replaceable as the user-provided part.