If you wanted to build a DOS PC, what would you build? The answer depends in no small part on what you expect it to run. Do you want a system that can run the oldest games? In that case you will probably want an IBM PC, XT or one of the earlier Tandy 1000 series systems. Perhaps even a PCjr. or a Compaq Portable? But those systems are often running PC Booters as much as they are running true DOS games. Fast forward a couple of years and you get into EGA and VGA systems. Now you are dealing with higher speed 286s, 386s and 486s. Even though many of the more speed sensitive games will fail to run on these systems, the classic DOS era is at hand. But suppose you want something with 3-D acceleration and high resolution color in mind. Then you are looking at Pentium systems and sharing drive space with Windows 95 games. Duke Nukem 3D, Fallout, Magic Carpet 2 require more than what most 486s will give.
I would suggest that most people probably received their first introduction to IBM compatible PCs and DOS in the early 1990s, "When VGA Was King." In those days, then-young adults like myself were in awe at the beautiful graphics of the King's Quest games, addicting world-building simulations like Civilization and complex role-playing of the Ultimas. We saved our allowances to buy a Sound Blaster card because systems did not come with sound cards as a standard feature until well into the mid-90s. We looked eagerly at the new CD-ROM technology, waiting for it to drop in price and salivated at The 7th Guest and Myst (and found out that cutting edge technology seldom lives up to the hype). PCs had something to offer that our NES, SNES and Genesis consoles could not.
Building a DOS system often addresses that era of early 90s gaming with the ability to reach somewhat back to the late 80s and forward into the mid 90s. Building vintage computer systems has become something of a niche hobby, but now one with very dedicated members. My own humble writings here and elsewhere may have made some small contribution to this phenomenon. But when someone like Lazy Game Reviews decides to post a system build video, it will get a great deal of attention. With almost 400K Youtube subscribers and videos easily ratcheting 100K views within a short period of time, he is sufficiently successful on that he does not need a day job. Although far many more people watch his Sims videos than his retro-computing videos, there is enough overlap that his message reaches many more people than anyone else I know of who
regularly covers retro-PC topics.
Here is his first video : https://www.youtube.com/watch?v=fbjYkPKRm-8
And here is his followup video : https://www.youtube.com/watch?v=g15J44xB2zU