The new Plus category of Chromebooks is an assurance that you'll get a higher level of performance and features but still at a reasonable starting price.
With Chromebook Plus, you're guaranteed to get at least the following specs, with a starting price of $399:
- 12th-gen Intel Core i3 or AMD Ryzen 3 7000 processor or better
- 8GB or more of memory
- 128GB or more of storage
- 1080p-resolution IPS LCD or better
- 1080p webcam with temporal noise reduction
You aren't understanding.
That's support for one specific software release.
It'd be like saying Apple supports iPhones for 1 year not 5+ years, because they're only on iOS version X for one year.
Linux devices get updates literally forever.