Sometimes it is a pity having to throw away still working but old
hardware. I have two Pentium 4 procecessors one with a functional
motherboard that I do not use anymore. The reasons for abandoning them
are speed and electricity consumption. Today's Internet requires
faster computers to be used properly with many sites mandating the use
of script. Paying online using old hardware has become next to
impossible and going in person to make payments is a time waster for
most people.

As some hinted out, using prohibitively power hungry, that is, old
hardware, is not viable anymore. The long term electricity expenditure
cannot justify using such hardware.

I have a T4400 Acer Aspire laptop that now I almost seldom use. The
reason is speed. Since most sites mandate the use of script, and I pay
my bills online, it is not practical anymore to use it.

Besides of technical reasons for boarding out hardware that still work
there are other reasons like speed and power efficiency.

--
If you can't explain it simply, you don't understand it well enough.
(Albert Einstein)
If you cannot make abstructions about details you do not understand
the concepts underlying them.