True, and the thing with laptops is that they are continually being pushed to be as small and thin as possible, and as light as possible or they won't sell. they also don't run at full power continually, so the heatsinks don't need to be large and hold tons of heat like desktops do. because they are often not under load continuously. so rather than storing the heat, they do their best to not generate it to begin with, and what the do generate goes straight to the fan to be displaced immediately. This is why it is so important to keep them clean and keep the exhaust port unblocked. They need to breathe. The other part of the problem is that most people don't know how to open and clean one out. Laptops are mobile, so naturally they are exposed to all sorts of environments, and get dirty fast, the heatsink fins are often closer together, so they get clogged just that much faster and easier. I think you'll all agree that a tower is far easier to work on. just lift the side cover. laptops often are not easily serviceable depending on design.
Also, Laptops have a shorter natural lifespan in today's market, astonishingly short. around 2-3 years on average before they are traded for a better one. The 2.5" drives are also unlike 3.5" drives in the way that they are moved around, especially while in operation. This is, and always will be bad for them, so their average lifespan is lower, especially when they're already pushing the limits on what they can do, particularly speed wise. those 7200+RPM drive motors get really hot for example, and many laptop makers don't heat-sink them very well, so they're continually getting bumped around while simultaneously getting cooked by their own heat, unlike their larger brethren. Laptops were originally designed to be work computers, not for games and labor intensive things, and I often think people forget this. The were not made (originally) to handle a lot of the things we make them do today. which is another reason SSDs have come down from the server market to be used in residential machines. For the longest time, the sole improvements on our computers have been things like the processors and graphics, while the hard drives just keep clacking away. It has gotten to the point to where HDDs just can't keep up easily with certain tasks, so if we want something faster, you gotta make it go digital instead of mechanical.
If you want storage space, get a HDD, if you want speed and lower power, get a SSD. I actually mix the two, putting my OS and low-write/ read-only stuff on the SSD, and all my heavily re-written, vital storage, and misc files on an HDD.