My 2 cents on the topic.
Are Powerpc's obsolete in 2016 ? Absolutely not.
A short history, came from NEC V20 , 8086 up to 80386DX desktop until my friend gave me a Pentium II-MMX in 2000 and told me explicitly to stop using DOS and install Windows.
In 2009 I bought my first smartphone an Iphone 4 because I felt that it had all items I wanted on the road, browsing, music player, GPS, calendar , phonebook which I could take with me all in one device.
At the same time I started to follow my CCNA Exploration course and needed a laptop , thus I bought a pristine 2007 Blackbook running Snow Leopard from a friend because I knew it was like new.
Went through all kind of Intel iterations until I ended with a Macbook Air 11inch Broadwell , a maxed out Mac Mini server model with a 27" Thunderbolt display in 2014.
Bought a iBook G4 just for the fun of fiddling with it and loved OS X Leopard which I never had used because it reminded me off Snow Leopard and was quite amazed how far ahead OS X was in those days compared to Windowz.
Went through painfull OS X upgrades, up to 10.11 which I feel becomes less and less what I want from OS in functionality and looks.
Saw the 12" Macbook arrive and sold my 11" Macbook Air a few days later for a Powerbook G4 12" , as a result of my disappointment in the price ranges of the Intel Macs and bizarre features .
Replaced the Mac Mini with a 2012 Maxed Out Retina Macbook Pro since I needed the RAM to run several virtual machines at the same moment and a bigger and faster SSD. This has now become my main workhorse which I mostly use because it is coupled to the Thunderbolt Display.
Upgraded the Powerbook G4 12" with a Newertech Battery and an IDE SSD which gives me 5 working hours of runtime and a cool and silent machine except when I'm pushing it whilst running a Virtual Machine and maxing out the RAM usage.
Messing around with OS X 10.5.8 , FreeBSD 10.3, Debian 8, Ubuntu Mate 16.04 LTS, OpenBSD 5.8 brings back my console and UNIX love that I've had every since college.
Bought a Powerbook G4 15" just because I found it in pristine condition for 100 EUR here locally.
I use my Powerbook G4 12" the most out of the 3 machines I own now, and I feel I'm really getting back for the buck.
Would I recommend a PowerPC to an computer noob ? No, you need to tinker and really love debugging, looking for stuff to keep it running.
Would I give a PowerPC to a family member ? Yes, since I'll end up installing and maintaining it anyway
Can it be used in 2016 ? Absolutely, just last week I had to verify if I could logon to the company VPN and couldn't get it working on the MBP Retina because I refuse to install Java.
Just for fun , I installed an older Citrix ICA client, discovered the Allow Java button in Webkit and tadaah VPN + Citrix Desktop from work were running 2016 style on a 2006 Powerbook G4 12", doesn't blink and runs even smoother than the HP Elitebook , 4GB , i5 ,Win 7 32 bit crap I have to use at work.
My colleague running 10.11 on his MBP Retina who did install Java discovered that he has to use Firefox now because Safari no longer works with the company Juniper VPN since upgrading to El Capitan, had him debugging his logon issues on my Powerbook G4 . LOL