Gents,
The type of duty described does age the battery and the power connection point of the Laptop. Assuming you start out with a new Laptop, and the this duty, you will get these results almost every time. I build and repair computers for friends and family as a hobby (laptops are repair / rebuild only), and see this quite often. Not only do power connections fail but so do USB, Headphones, etc., from repeated in/out cycling.
Running on solely battery power only lasts a few hours. Hence the multiple recharges per day. The operational life of the battery diminishes a little bit with each full charge (Quicker with incomplete charging.) The battery does have a limited amount of recharging cycles to it's life. Similarly, the plug has only a certain lifecycle. To avoid this, go to AC power and leave the battery out. And don't cycle the power connection point more than absolutely necessary. Taking the battery out of most laptops takes less than 10 seconds, and popping it back in less.
The hardware in today's laptops are lighter built to hit certain price points (and profit margins) so after the warranty is expired, long before the motherboard, CPU, or Ram fail, the periphery goes. Even doing this, you will need to replace the battery every few years - but you won't recycle the laptop for a long time. IMHO, working off a laptop on a couch is not good ergonomics. Better to work off a table with a supportive chair. (There's a reason offices have desks). I was a road warrior with a laptop for work for ages, and spent long hours working from them, with negative results.
Workstations with a desktop make a lot of sense for 8 hour per day computing. You can create good ergonomics while preventing injury and pain. Corporations have gone to laptops instead as they have become cheaper to purchase, operate, and support IT wise. Yes it's all about the Benjamins! And the employees have gone along with it as they think laptops are cool. A side benefit to employers is folks can, and do, work from "anywhere" and very often put in a lot of free hours on their own personal time. (Trust me I was one of them). For many years I worked out of my home office; but always got a "docking station" with dual monitors, external keyboard & mouse. I saved the working off a laptop for when I was doing the road warrior part; but even then tried to find a good place to work from. Off my lap was a last resort.
Boy are we off topic here...Sorry