A new Internet based tool is available now to simplify making calls with spoofed calling number. The main difference with this tool, is that it only accepts Bitcoin, so it is more anonymous. It certainly lowers the bar provides another tool for those performing social engineering. I included a few links below the image with more information.
Of course serious social engineers and phone scammers have their own tools, usually sitting behind their own Asterisk server, so they have a lot of control over what their calls look like.