If you’re capable of doing it and have the time then outsourcing it doesn’t make sense from a business perspective unless you want the time off and are happy to take the hit financially.
I find it hard to outsource coding as it’s something I know that I am usually perfectly capable of doing. However if it’s something that’s dull or I don’t want to do and I can spend my time more efficiently doing something else then it makes business sense.
For artwork I suck so I nearly always outsource or use stock. I’m too slow at modelling so paying someone $X an hour is almost always better so I can focus on the dev side of things