You could install PureOS on other hardware, if you wanted:
https://www.pureos.net/The Purism hardware is certainly an excellent set of design tradeoffs - for a particular risk profile of user. If you're a basic user, you're not that target market, and the hardware features that Purism offers are of remarkably little value to you. Quite simply, if you can't explain how trusted boot works, what evil maid attacks are, know something about firmware image verification, etc, the hardware isn't going to be of any particular value. The hardware cutoffs are nice, but unless you're seriously worried about that sort of thing (or are taking the hardware into places where wireless is disallowed), it's not of much value to a typical user.
The hardware isn't magically secure. It's a low volume, high priced laptop that's built around some of Invisible Things' design principles, with a minimal amount of firmware in the various hardware controllers, an auditable main flash chip for the firmware, a set of features well suited to heavy virtualization based isolation, and a decent OS distribution running on top of it. If you want something to run Qubes, it's a fairly good option - and I certainly agree with their design choices and their work to neuter the ME, but... I also know what all that means. For what it's worth, I don't (yet) own one.
But it's not going to prevent stupid, and if you're not interested in putting in the time to learn a new OS, don't buy one. Get a used business grade laptop, flash the firmware to the latest version, put Win10 on it, use Firefox or Chrome with some ad blocking/tracker blocking extensions, and call it good.