I do run a Neo3 for years 24/7 without problems. Please avoid the rage. Of course, you may have a faulty unit. At the same time, if you want to run a relatively bare board, you should be ready to learn how to do it.
This looks like a connection issue before even being able to connect to the board.
Can you connect to any network using the USB Ethernet adapter? Your home router, for example?
Could you maybe also connect the board to your home router using Ethernet?
Are you sure your UART chip supports baud 1500000? CP2102 does not, CH340G and FT232RQ do IIRC (please re-check before buying).
Best
Lukas
