Building a computer is easy, but as I've learned from my last core i7 build, building a computer that actually is stable, is not cut and dry. I'd say the early 2000's were easier as hardware was not as fussy. Ram etc.. basically worked if it fits. Now you have to check compatibility lists and all that crap and DOA/flaky hardware is all too common and it's rare a brand new build "just works", whether there's faulty hardware somewhere and you have to play the "buy a new one and try it" game or perhaps some kind of incompatibility or known issue etc... Having to cross reference compatibility lists can be tedius as the product IDs they use may not be searchable on whatever retailer you use as they may not use the same product IDs so trying to find a motherboard and ram that is certified compatible, at a single retailer, can be tedious.
Actually, I'm of the belief that it's gotten easier and easier as time has passed to build a computer. Gone are the days of having to set DIP switches on the motherboard with every manufacturer doing something completely different. Parts are much more tolerant of being slapped in here and there with almost any other maker's parts.
Honestly, if you don't try to buy the absolute cheapest pieces of junk for parts, have yet to encounter any assembly problems on boot or operating. The RAM choice these days seems fairly inconsequential....Corsair, AData, Kingston, GSkill, Micron.....doesn't seem to matter. Have dropped in darned near any of it on Intel and AMD boards from the last decade....all worked.
Video cards shouldn't be an issue at all. Power supplies may be "touchy", but only in relation to Haswell and its deep sleep issues. Outside bottom rung ps's, haven't seen problems yet.
Hard drives, outside the 3TB "barrier", are a dime a dozen and all work. And that includes SSD's.
The problems I've seen people having is getting settings in the BIOS set correctly, more problematic with the more expensive boards with their wealth of settings...far more settings than you saw in the early 1990's, which could create problems for the uninitiated or unskilled.
Outside that issue, assembling a computer today is a snap. I put one together coming home from MicroCenter....wife drove, I sat in the back seat and built it. When we arrived home, it was ready to be booted and OS loaded, which it did without problems at all. Was ready for delivery the next morning, although it was a bit of a drag doing all the OS updates that night.
Now, to me, tech savvy is more than just putting together the jigsaw puzzle of a desktop, something you can teach a 12 year old to do in one sitting. It's more understanding the tech itself. What's the difference between the various USB standards? What's Thunderbolt?
If one can understand the tech around and intelligently talk about it, not how it was made, but pros and cons of using this or that, one can be considered tech savvy.