I just installed my own dishwasher, it was ridiculously easy. fwiw...
Have done it too but it's not for everyone. So many ways to mess it up and probably not something most people should try if they aren't detail oriented
- Attaching supply hoses, could easily do too loose or too tight and have problems behind the cabinet later
- Drain hose high loop must be the proper clearance (or do an air gap)
- Tucking all the wires and hoses properly into the cabinet and not under or behind the appliance
- Making the electrical connections if a plug isn't factory connected is another competence needed