"PDP-11 with UNIX opened the floodgates for inexpensive interactive computing, which then led to an explosion of office productivity. "

Well before we get too misty eyed: "inexpensive" needs looking at "for inexpensive interactive computing".

I'm not old (55) enough to have really got to grips with a PDP11. I do still own (yes: present tense) a C64 from 1986. The C64 was bought by my dad via the NAAFI in West Germany so I have no idea what it costed. Let's wind forward a bit:

I had a 80286 based PC in 1987ish with 1MB of RAM, 20MB RLL hard disc. The graphics card (ISA) had a whopping 512 bytes of RAM. That thing costed about £1200. I added a 80287 later at about £120 so I could run a pirated copy of AutoCAD.

In 1990ish I had a 80486 with 4Mb RAM and 40MB HD - that costed something like £1600.

Nowadays £1600 will buy quite a decent laptop and 35 years of inflation.