I absolutely ADORE Snowdonia/North West Wales/West Wales, and go there a couple of times a year, for long weekends. Love Snowdon/Llanberis area, Betwys-y-Coed, Capel Curig, Llangollen, Barmouth, all of it!
Would I like to live there? No. I mean some people do and that is lovely for them. But I have spoken to some (English) people who moved there after buying a B & B/Guest House, or a shop, and whilst they like it, they say it's grim in winter, the trade is scant, and over the year, they barely break even. And people under-estimate how long it will take to get to places... eg; to a major hospital. Or anywhere really! Phone signal and internet can be sketchy!
Barmouth (for example,) is gorgeous, and that whole area (Machynlleth, Dolgellau, Mach Loop, Horseshoe Pass, Fairbourne etc,) but it takes soooooo long to get anywhere from there, because as lovely as North and Mid Wales/Snowdonia is, the traffic routes aren't great, and public transport is poor. That's why property is so cheap. That, and the fact that there is not much there except tranquillity and beauty.
DH and I moved from a busy large town to a little village in the sticks (from West Midlands to North Midlands,) just over a decade ago, and we are 15-16 miles (half hour drive,) from most places really - including any banks or hospitals or train stations ... (We just have a little market town 3-4 miles away with no banks and not that many main shops really.) Even the market town only has a couple of buses a day to just 3 towns 14 to 16 miles away in different directions. We have no train station for 15-16 miles.
We also have no public transport in or out of our village and zero shops. Just one pub, a Church, and a Parish hall that houses a dozen or so hobby/social groups. It's a very friendly village though, our neighbours are lovely, and the area is gorgeous... River, woodlands, canal, farmlands, fields, lots of beauty, so we love it and have no plans to move anytime soon. But it is a bit rural/off grid. And having had the culture shock from Town to tiny village 15 miles from most places, I know I would not want to be MORE rural/further away from places. I mean we got used to being out in the sticks, quite quickly, but yeah, there is much less closeby than there is in a town! (Obvs!) 
I think the idea of living in Snowdonia is much lovelier than the reality would be (for most!)
!