Re: Z80 was a more sophisticated processor
Essentially an 8080 designed by people that left Intel.
the 8085 was Intel's answer to Z80. The bankswitch on Z80 allowed fast context switch to a scheduler for Round Robin multitasking. Ultimately it was CP/M that made 8080/Z80/8085 popular along with Wordstar and Supercalc (vs Visicalc on the Apple II). The CP/M computers tended to be more business orientated with 80 column displays, monitors rather TVs and at least one 5.25" or 8" floppy. The original PCs. No surprise CP/M was ported to 8086 and the bought in MS clone (MS DOS / PC DOS) was the main OS for IBM PC. The 8086 / 8088 wasn't a "real" 16bit CPU like later 80286 (which ran Xenix and UNIX), being basically an 8080 with segment register for addresses outside the 64K byte block and a few 16 bit instructions.
Whatever about 6502 vs Z80 (or 8080/8085), the 8088/8086 was crippled junk compared to almost all other 16 bit CPUs. No comparison to 68000 or indeed some 16bit parts IBM used. The IBM PC wasn't really meant to be the success and industry standard. Sadly it was and it held back mainstream PCs till maybe NT4.0, Windows 2000 or XP, because Win9x / ME was a garbage OS, basically Win3.x shell with Win32s and Explorer lipstick on the pig. Win9x had the evil 8086/80386 pseudo 16bit/32bit hybrid architecture under the hood which is why it ran so badly on the Pentium Pro compared to "real" 32 bit NT 3.1, NT 3.5, NT3.51 and NT4.0
I used the Z80 in many projects and also some CP/M desktops (last was the PCW8256/PCW8512). However the 8088/8086 based PC and MSDOS made me wish the 8080/Z80/8085 had never existed.
The PIC was originally a peripheral for I/O on a more powerful CPU. The onboard EPROM and later Flash memory coupled with cheapness and Zero extra chips meant it was a success for simple projects. The Flash version of original PIC1684 still sold last time I looked. Using Basic, C or JAL on a PIC18Fxxx that only needs a capacitor and socket to be a USB slave and can be reprogrammed easily in circuit means the simple PIC still lives despite some ARM Cortex as cheap as 50c.
Who would use an x86-64 Intel/AMD part today for anything portable if you didn't need legacy Windows applications?
The ARM was born from Acorn's use of 6502 and their horror of x86. So in a sense the 6502 won. There are more ARM CPUS made in a week than x86 parts in a year. The Raspberry Pi is supposed to be the modern take on BBC Micro (6502). It's little more than an ARM CPU for a phone /tablet on a breakout board. A brilliant alternative for projects unsuitable for either a PIC or a full $200 tablet. Choice of various OS (RiscOS, various Linux distros and if you are bonkers, an embedded Windows that can't run any regular Windows applications, the Linux has ARM versions of Gimp, Libre Office, Firefox etc, most of what is common on an x86 laptop with Linux)