It was infuriating how many things plug in properly but don’t actually convey the capabilities I wanted. Even picking the wrong DisplayPort cable will limit it at 30hz.
I understand there are explanations that are perfectly cromulent to engineers. But they aren’t any good to the other 99% of users.
Converting Thunderbolt to DisplayPort is technically possible, but completely pointless because both TB2 and TB3 are natively DisplayPort compatible, at both protocol and connector level.
One exception: it's useful for a Thunderbolt Dock to have a Thunderbolt connection to the host system, while offering another Thunderbolt port that can emit a standard, un-encapsulated DisplayPort signal. But for an adapter with none of the other ports offered by a dock, it is generally pointless.
Because nobody in China uses DP
It works well for 4k@60Hz and it's one of the cheaper solution at ~ 20$ per cable.
Cherry on top, it's sold by AnkerDirect on Amazon, which is the genuine manufacturer.
UK https://www.amazon.co.uk/Anker-Adapter-MacBook-Thunderbolt-C...
US https://www.amazon.com/Anker-Adapter-MacBook-Thunderbolt-Com...
I have a monitor that's 4K/60 if I directly cable to it, but often only comes up at 30Hz (or 4:2:2 colour mode 60Hz) if I use a KVM. Yes, the KVMs were sold as "4k/60 support" and I've tried two different ones (one HDMI, one DP). One machine works fine, because it's a sucky pre-Cambrian laptop dock that isn't even TRYING for 4K, and the failing one is a desktop with a GTX1080.
What's interesting is that it seems like it only happens in Windows. I experimented with a FreeBSD install, and the drivers there reliably hit 4K/60 even with the DisplayPort KVM in the way.
I suspect the drivers must have different strategies to probe the capabilities of the device and cables, and the Windows drivers interpret them more conservatively.
So I ended up using the KVM as a $100+ USB switch and just toggling the inputs with the monitor's own buttons. (I gather there's software that could do automatic input switching via DCC configuration channels, but one machine is corporate-managed so I can't just stuff random software on it)
Most of them, while otherwise being perfect, also tend to lack some essential feature.
Here’s the cheapest full featured USB-C dongle/dock on german Amazon (a few months ago): https://www.amazon.de/Multiport-MacBook-Adapter-Dockteck-Mic...
Goes well with this extension: https://www.amazon.de/gp/aw/d/B08MXL8JGF
Conclusion: A minimal USB-C docking setup costs 45€. Quite a bit for something essential on some laptops.
"See, it's like you made a pizza with cake flour. It won't taste good, it won't cook quite right, and you'll be disappointed even though it kind of works. There's nothing bad about cake flour, and it works really well for what it's intended for, but it can't be used for everything."
"Imagine you were using bad steel when you were forging a blade. It'll crack, roll or worse, but it'll still look vaguely knife-like."
"It's like you're wanting to play electric rock music but you're missing a few strings and you don't have a pickup so it's really pretty much just a weirdly-shaped banjo."
This is a pattern that literally every human understands in their own niche.
"The Pizza was made with Cake Flour so it's Low-Quality."
"The Blade was made with Low-Carbon Steel so it's Unsafe and Weak."
"The Cable was made Without the Proper Materials so It's Subpar.
"Just like with flour, keep them in their own containers, and keep track of which container is which. If you lose track, bake something small as a test or test the cable by plugging it in."
Now, you can use both types of flour and get a cool result but cake flour on its own will leave you with a rock with tomato sauce and cheese, most of the time.