These PCs are laughable. You’re asking covid pricing on PCs that are next to worthless right now. 500 dollars for a 4600g and no GPU? you’re living in the past. Give these PCs a wide birth.
Let’s build it ourselves just for comparison… pricing based on Amazon searches.
~$100 - AMD Ryzen 5 4600G
$79.99 - Gigabyte B450M DS3H WiFi (lower-end mobo with similar specs)
$50+ - Tempered glass mATX case (Zalman T3 mini - low-end price… these can cost a lot more)
$55+ - 650w 80+ Bronze Cert Power Supply
$45+ - 1TB NVMe m.2 SSD
$32+ - 16GB DDR4 3200 RAM (2 sticks; basic)
$45+ - Windows 10 Home (cheaper options available, but most likely OEM/Dev or not legitimate)
$20-$60 - Extra RGB fans (not included in total below)
Total: $406.99
If you have a couple hours of spare time to build it yourself, you can definitely save a decent amount of money. I wouldn’t call these laughable… a little pricey, maybe. People use computers for different reasons, and what wouldn’t work for one person, may work just fine for another, and last them years. And there is some level of convenience in buying a prebuilt PC (build time, support, warranty, etc).
On the warranty thing… building yourself means that if you have issues with any hardware beyond seller 30 day return policies, you would have to handle those yourself via each part manufacturers warranty/RMA options, rather than having just one company to deal with.
All the parts I listed are lower-end/budget ones… which is probably similar to the parts in this PC. And it is listed as a “starter” system, which is meant to be able to be upgraded.
I’ve built dozens of PCs over the years… starting around when the 486 DX4 100 was the popular chip on the market. You can generally always build a PC cheaper than buying one. And it can be a fun project as well, especially if you have kids that are into that type of stuff. Just know what you are getting into if you go that route.
Microsoft ended free upgrades from Windows 7/8 to 10 in September, so many of the ways to get W10 for less are gone now.
(In the past, I was sometimes able to install W10 on 100% new computers using OEM W7 keys I pulled from retired computers. It didn’t always activate, but I also didn’t question it when it did.)
As for when I started building … since the days of the 8088. 
(Note that I am not staff. I just volunteer to help out on the forums.)
Dang… still had one last warehouse computer running Windows 7. I figured they’d shut that down at some point though. Guess I should have gotten on that. I did get quite a few upgraded from 7 to 10 over the past year or so… but most of them are gen 6 or older Intel CPUs, so going to have to replace a bunch sometime in the future when we have to start going to 11.
I’ve had a few PCs with 8088 procs… never built any back then, but definitely turned in lots of high school book reports written in WordStar running on CP/M 
Probably 3rd gen or older? 6th gen was when W7 support tapered off. At my work, I was finally able to retire the C2D machine as the user retired as well.
There are workarounds to getting W11 on “unsupported” computers but I’ll be riding W10 closer to its end. Running Mint on multiple machines at home, though.
Oh yeah, a good portion are 3rd or 4th gen… but I do have a handful that are 6th gen too, so just barely don’t make the cut. All these old systems are random refurbs we picked up over the years. And they’ve pretty much all been relegated to the main warehouse or our fulfillment warehouse to use as network shipping clients. So they can ride 10 for a while longer and be fine. Most the front office folks have newer laptops that already have 11, or are at least new enough to upgrade to it.