DIY gives you more flexibility, but also more maintenance.
More maintenance? Setup is harder for sure, but after that no more maintenance required if you don’t feel like it. To be frank the amount of maintenance is usually corelated with the amount of crap you install. a TrueNAS Scale will run just fine, maintenance free most likely for more than 5 years, however a clean Debian install with a simple Samba server (install via apt-get install) + FileBrowser (webUI file explorer) will last indefinitely without maintenance. Simple tools fail less.