I wouldn't say it's uncommon. Not the easiest to carry around with you unless you have the bag/case for it, but anything beyond a point-n-click game makes sense to use a separate keyboard. Much easier in terms of ergonomics if you can put things (laptop & keyboard/other accessories) in a more comfortable setup. Also protects your laptop from excessively heavy keystrokes impact or shaking the components if you get caught up in the moment.
When I used my laptop at home, I definitely attached a keyboard. For me, it had a more natural feel. Typing in general and gaming are easier. I learned to type on this type of keyboard. As stated by others, it does save wear and tear on the laptop keys.
Depending on the attached keyboard, it can provide more benefits for gaming. Some mechanical or gaming keyboards have n-key rollover support, shorter actuation distances, macro programming, etc., which can give you the edge in gaming. I actually recently reviewed a keyboard with magnetic switches, which has adjustable actuation distances, so you can register a keypress in as little as 0.4 mm of travel distance before you have to let go of the key and press it again to register the next keypress. This can make you really quick at games where you have to repeatedly spam a key.
I've always preferred using a usb keyboard for long sessions. I think the shape and tactile feedback of the keys allow me to have a more enjoyable experience. And since the usb keyboard is not part of the laptop, it's easy to clean, fix, or replace.
Yes, it is relatively common for gamers to use external keyboards when gaming on a laptop. While laptops generally come with built-in keyboards, many gamers prefer the tactile feedback, customization options, and additional features offered by dedicated gaming keyboards. External gaming keyboards often have mechanical switches that provide a more satisfying typing and gaming experience compared to the membrane-based keyboards commonly found in laptops. Mechanical keyboards are known for their durability and responsiveness, which can be beneficial for fast-paced gaming. Furthermore, gaming keyboards often come with programmable keys, customizable backlighting, and extra macro keys that can be assigned to specific in-game functions. These features allow gamers to personalize their gaming experience and optimize their gameplay. Using an external keyboard also provides more ergonomic options. Laptops typically have a fixed keyboard position, which may not be comfortable for extended gaming sessions. With an external keyboard, gamers can choose a keyboard layout, size, and position that suits their preferences and ergonomic needs. Overall, while many gamers use the built-in keyboards on their laptops, it's not uncommon to see gamers opting for external keyboards for improved performance, customization, and comfort.
