Dell Vostro 5370 docking station

Glad I could help!  I'm really surprised that Dell put out a 13-inch system that doesn't support being charged over USB-C, since USB Power Delivery would absolutely provide enough power to run that system.  I guess there's still a bit of cost to be saved by omitting that feature, just as Dell even in 2018 still ships some systems with 10/100 Ethernet rather than Gigabit, even though the Latitude models all moved to Gigabit over 15 years ago.  But it's definitely confusing to see USB Power Delivery mentioned on the product page, since some people naturally assume that this means the system can be charged that way, but technically USB Power Delivery can negotiate power in either direction, so on some systems it means that the USB-C port can provide more power than a typical USB connector, which typically means it can do 15W for supported devices rather than the 4.5 - 7.5W typical range for regular USB 3.1 ports.

For the docks, the Dxxxx series docks are useful in two cases.  The first to provide a dock solution for systems that don't have any "traditional" docking mechanism, such as the outgoing underside docking connector or the more recent USB-C (with display output capability) and Thunderbolt 3 connectors.  And the second case is for users who want to run more displays and/or higher resolution displays than their GPU and/or display connectors would normally support.  The D6000 dock for example can run 3x 4K displays.  The reason this is all possible is that the DisplayLink chip inside those docks works in collaboration with a driver you install on your system, which causes the displays to be treated as "indirect displays".  This means that rather than the GPU directly controlling and outputting to them, the CPU and GPU render display data for these "indirect" displays and then compress it and transmit it as regular USB data traffic to the dock, where the DisplayLink chip decompresses it and outputs it as video.  That's why these docks can be used even with systems that don't have native video output capability through a "traditional" docking connector and why you can exceed the resolution and display quantity limits.  The downsides though are that all this resource utilization to compress display data and transmit it over USB means that you can end up seeing compression artifacts like blocky pixels and/or judder-y motion.  This is especially likely in situations such as your CPU and GPU already being heavily utilized, your USB bus already being busy with a lot of other traffic (large file transfer to/from an external hard drive, for example), running multiple and/or high resolution displays that requires more display data to be rendered and transmitted, or doing things like full screen video or gaming where a lot of the display area changes at once, again forcing more display data to be rendered and transmitted.  Oh, and on systems that have both an integrated and a higher-performance discrete GPU, a Windows limitation means that the discrete GPU's horsepower can never be used for anything displayed on indirect displays.

So if you only need to use external displays for basic productivity things like Word, email, and browsing where much of the display area is static most of the time, then especially if your system's connectors give you no other alternative, the Dxxxx series docks are perfectly fine.  After all, external displays even with limitations are certainly better from a productivity standpoint than no external displays at all.  But if you have a better option and the regular GPU limits that apply in that case (e.g. dual 1080p displays for the WD15) aren't a limiting factor for you, then you definitely want to go the latter route.  Enjoy!

Thank you for your answer. In fact, this description fooled me. I contacted Dell support and confirmed that this model can not be charged from the usb-c port, which is incorrectly indicated in the technical specification... And also thanks for giving advice about docking station!

I have the Vostro 13 5370 laptop and although it comes with a barrel type charger, it also charges via the USB-C port via the 65W USB-C charger that came with my Chromebook 3380.