IMHO gutters rate a 10 only over entryways, HVAC, any fenestration saved from leaking from hard storms.
Gutters rate a 1 when you are on a slab-on-grade concrete with perimeter grade well prepared to carry "flood" waters off & well away. Slabs-on-grade perform best when all sides graded have equal moisture content, so support is equal and nothing wants to crack.
Many have borrowed from the past in using gravel/bull-rock as erosion control & roof-runoff-catch in garden beds, then drain this off to French drains or less as required.
In-the-day, dry wells also served in such a capacity ... last publicly seen in Aggieland = TAMU Campus Course Clubhouse. Dry wells are located at roof valleys' spillage but also when a long gutter's leader/downspout needs to dump a large load.
If you go gutters, the smart money is on
6" w/leaf guards that work
leaders at outside foundation corners (where the foundations are needy/thirsty and tend to droop = cracking)
grade pipes 10ft long outbound
options include
mosquito-proof water barrels, also with 10ft overflow grade hoses outbound
in-ground septic-cisterns w/pump
piping to a pond, garden
Ten words or less ... a goal unattainable