That's not really comparable hardware. The AS6804T has four 3.5" HDD bays, Synology hardware generally offers two to eight bays. They're NASes, the NUC is just a mini computer with little to no built-in storage capacity. It's not about the apps here.

Plus, 4 SSD slots and 16GB ECC RAM which is upgradeable to 64GB. That thing is a sleeper.