To be perfectly clear, Trisquel works perfectly on some modern hardware. But
that modern hardware has obstacles to freedom, and depends on proprietary
boot firmware. See here for details:
https://libreboot.org/faq/
Think Penguin is a company that uses this modern hardware to produce
computers that at least work perfectly with Linux-libre (and hence Trisquel),
but they depend on (and are shipped with) proprietary boot firmware. So it's
a fallacy to assume that Trisquel needs 8-year-old hardware to perform well.
It's just that you need 8-year-old hardware to get an x86 system that works
with 100% libre software... with the exception of embedded, unchangeable
firmware found in various components.