Updated June 29th 2021.
The main reason you are going to want a fanless laptop in 2021: it's because it's going to be totally quiet, especially when paired with an SSD. The bottom end of the fanless market also tend to have no power and be pretty gutless while using a mechanical hard drive (whirring sounds and clicks), though a good quality mid to premium Ultrabook is also going to be powerful.
After using a fanless laptop, you are probably never going to be able to go back. Even really quiet laptops are going to be disturbing. Once you go fanless you can never go back.
It is important to note that most fanless laptops are mostly built on low-power hardware platforms that are budget laptops for everyday tasks. These laptops are not going to cope with multitasking or demanding tasks. Modern laptops are designed to do whatever a desktop PC can also do, so if you are prepared to go above the $1500 price point, then you will be able to get something that will do these tasks well. Considering that a premium end mobile phone is now around the $2000 mark, it isn't unreasonable to expect a great notebook computer to be at least this price also. After all, the old adage that you get what you pay for does ring true here and laptop computers can do so much more.
No fans, and no spinning HDDs equals no noise. Less moving parts also mean less can go wrong and through the right design, power consumption is also greatly improved. This also leads to better battery life.
There are two approaches, either take all the performance out, or reengineer. This is where Venom have done incredibly well with their award winning Venom BlackBook Zero 14 as it carries a similar philosophy to how Apple and Samsung have designed their premium smart phones (smart phones are fanless also). Passive cooling when done well does work with performance components, as Venom have proven.
At MLN we have been selling and servicing laptop computers for 20 years, and have been a Venom Authorised Retailer and Repair Centre for 9 years. The fanless option is a fantastic way to go forward and we promise you will never look back.