It’s a lot faster and easier than it used to be. Things like xUnit in the .net world make setting up tests friction free to the point where I question a codebase that doesn’t have some kind of basic unit tests. It doesn’t make mock testing or integration testing easier but I would argue if you know the base code and logic is sound those tests are less relevant.

One thing I found is that if testing is easy, your code structure does change a bit to aid with a “test first” approach and I don’t hate it. I thought it made me slower but it doesn’t, it ensures that when all the ground work is finished, the gnarly part of wiring everything up goes much faster.

Yeah I've found the same, having good test discipline influences my code design in a positive way because code that's easier to test is also code that's easier to integrate and understand.