It's not about saving money, I would do it myself it it cost exactly the same as a dealership.
The reason is I simply don't trust them to do the same level of care as I would, especially Stellantis dealerships. Over the years, I've grown tired of paying other people to screw it up. Especially occurs on the more basic cheaper jobs, since they post the lowest paid least experience techs on those.
Minor things like putting in too much oil is the most common offense, which I usually have to drain out myself with a siphon. Or leaving a mess for me to clean up later. Maybe a 4 hour wait that requires me to go home and then back again to pick the truck up. Not using the oil & filter I prefer, how do I know for sure they used what I paid for?
Then there is more rare and serious things, such as forgetting to change the oil filter, sometimes dinging a door, staining or scratching something on the interior, or actually forgetting to put oil in until after they turned on the engine and I guarantee you that won't ever get mentioned to the owner.
For me, no one will do a better job than me, I actually find it enjoyable and as a side benefit it's actually cheaper and quicker.