Unless you buy something from System76 or do very meticulous research on hardware support and build your own, Linux is not going to be seamless out of the box. But the real highlight is that it can be seamless at all these days.
My PC has four GPUs, 128GB of RAM and a deca-core CPU. I have four monitors, a bluetooth mouse, and I almost never turn it off. Instead, it automatically suspends. When I'm away from home I can ssh into my computer if needed. I have daily backups that are essentially seamless.
Now, it was difficult to get to this place. I would say that Linux is, and has for a long time been, rock solid if you're not using a GUI. In my opinion, the single greatest impediment to "Linux on the desktop" is xorg, which is terrible (to put it mildly). Nouveau is absolutely crap, especially since Nvidia puts out its own drivers. But my point here is that after a few days of careful installation and setup work, I have had a seamless desktop experience for something like eight months.
What needs to happen for Linux is a software company that takes something like Debian, fork it and dramatically bring it up to wider compatibility with modern hardware across the market. In some sense that's Ubuntu, and it shows in how easy my daily experience has been.
That being said, I only use Linux for server-side work, and I can easily say that it is every bit as stable as any other server OS I've used, and has been for a very long time. There are plenty of weedy areas to play in if you want to, of course. But if your goal is It Just Works, you can do that, too. Perhaps most importantly, you can do it easily, with just a little foresight during the spec stage of planning your project.
This is not to disparage the kernel developers, package maintainers or the distributions themselves - there's a lot of people doing excellent work without being compensated at all. However let's not kid ourselves - linux can still be tough.