Ever since the first gaming laptop, there have been people commenting on how impractical and a poor value these things are. While this is true for many people, there's obviously a market or they wouldn't keep making them.
I travel a ton. It's true you can't pull these things out in an airline seat, but when you're stuck in a hotel for a third of your life it's a godsend. I have a nice desktop PC at home, but having a house and family to take care of it doesn't get used as much as my gaming laptop. I can play Microsoft Flight Simulator, one of the most demanding games in existence, at full settings with my game controller and head tracking, and it's a smooth and fun experience. I can run any game out there and it runs and looks great. As far as screen size, when I was a kid a 17" CRT was a thing to brag about.
I do pretty well for myself these days, so I have a desktop, a gaming laptop, an ultrabook, and even a Steam Deck, but if I could only have one PC, it would be a gaming laptop. Considering the cost divided by how much more of my time I can spend with it, it's the best value and most practical PC someone like me can get.