Yeah it's BS. I did a hypothetical parts shopping for a PS5-equivalent PC and the cheapest you can get is probably ~ $780. Which is obviously more than PS5's $499.
However, you can theoretically pay less in the long run if you were also subscribing to PS+ for the entire 7 or so years of a console gen primarily for online play, whereas online play is free for PC. Because at that point you're looking at $499 PS5 (disc edition) + ~ $350 (PS+ Essentials for 7 years, assuming you could get a deal of $50/year and this was before the price increase), or $849 when all's said and done. That's about $70 more than a PC equivalent PS5 would run you for.
That's actually how Linus should've looked at doing the comparison, not with the way this video did. But even for that comparable hypothetical build, I had to search on a deal for a couple of the parts, meaning the common price for said parts is a bit higher. Also had to go for the cheapest possible casing. Honestly I'd say you should probably spend at least another $50 for a more robust casing, KB&M...and maybe for a slightly better GPU another ~ $50 on top of that, but you're still within spitting distance of what an actual PS5 with 7 years worth of PS+ Essentials (on a really good deal) would net you.
A person elsewhere brought up a really good point about PS+. People tend to use it only as a 'cost' measure in these kinds of comparisons. However, due to the included games, it can also save money for people. That's was the experience of the person who brought up this point - they paid for PS+, yes, but the value of the included games (which meant they no longer had to purchase those games) paid off the subscription cost annually.