Not only that, but you'll almost certainly have to junk the entire machine if a key component like the screen or the keyboard quits working,
Not that I'm a huge fan of laptops when you don't
need a laptop[1], screens and keyboards are utterly replaceable. As are the optical drives, wireless modules, batteries, hard drives, hinges and the cases themselves[2], some (not all) have an as-easily-replaced graphics module. Maybe not for the faint-hearted, but those that are more hardy can even change processors and replace broken ports (USB ones are a bugger for being broken, as well as the power socket).
None of the above will necessarily be
cheap to do, but (depending on the model, its age, demand and supply) it
might be easy enough for you (or your friendly local expert who isn't inclined to charge an arm and a leg) to change a keyboard (or even replace a single lost key-top!).
But laptops
do tend to age faster (wear and tear, and having a generally lower top-end compared with contemporary desktops) so replacing is probably just as viable, if finances allow, and gives you a new machine feel. (And "new machine 'how the hell do I do this under Windows+1'?" problems...
)
[1] I find it annoying when laptops are bought just for space-saving reasons, and will
always be used on the same kitchen table. There's plenty of slimline desktop-type units that can be shuffled behind a cupboard, along with the flatscreen, keyboard and mouse, when not in use, and would still be overkill when it comes to playing Solitaire, or whatever it is that the owner says they want to do with the machine... Not that this is the situation given here, but it's just one I've frequently encountered...
[2] Although if you have to replace
all of these, at once, get a new one.