Matt Risinger on youtube has some good ones. Most of his videos also have comparisons of construction methods, too. New vs. old, expensive vs. cheap. Other videos have some 'best practices'.

Here's one about corners some contractors often cut: 10 DUMB (and Common) Building Practices https://www.youtube.com/watch?v=LuUxUt6MwIU

Here's another about his regrets about how he remodeled his own house: https://www.youtube.com/watch?v=4HYROAFgp7Y

I don't have a good playlist or show to link off-hand, but here's a wonderful video about someone finding terrible things in their old house: https://www.youtube.com/watch?v=_v33Gb2xPhU

In general you want "fixing old houses" videos that focus more on the tear down and guts and less on the "look how pretty my house looks at the end" before & afters.