I REALLY do think you save money going to PC gaming in the long run, because I did so during college when I had a fixed budget. I obviously needed a computer to do basic tasks, so spending some more to make it play games was cheaper than buying both a decent work-only PC and a console.
You mention people frowning on third-party sites, but I don't think it's hard to find one that is legit. I've used greenmangaming for years, who have a 20-30% coupon on new games almost perpetually, and I've yet to not get what I ordered. Suddenly the $60 day one big game became a $35-48 purchase instead. The savings weren't just an excuse to spend, but the only way I could get these games at all.
Then the PC games I played with mod tools kept adding additional content, letting me get more out of a game before going out to get something new. Instead of $50-60 a year on Xbox Live (later PS+), I could use that money on new or old games.
While brick and mortar $60 AAA games are a thing many people buy, there are certain PC F2P games that drew a large audience. I met people who don't even really play games much who were into League of Legends, or gave up Battlefield to play Planetside 2. Hearthstone draws in more people than the average AAA game as well. If anything these service-based multiplayer F2P games are becoming a thing the more casual people on the platform consume now.
PC gaming still has more of the technical hurdles than consoles, and if you don't build it yourself will cost more at the beginning...but consoles have adopted PC features that brought along complexity and a loss to "pure" plug and play. PCs have also gotten only more user-friendly and automated. I think that and the additional ways to save money is why more and more people have flocked to it in the last half decade.
Steam's growing userbase can't just be hardcore gamers and new kids, there is a portion of console folks moving over (even if just to be a secondary platform).