Some of my best allies in golf have been actively involved in both the bidding for and organisation of the Curtis Cup at Conwy, so this comes with that friendly disclaimer. As Thomas Dai says, the whole locality and Welsh government got behind the initial bid, following a number of successful R&A and LGU and European events at Conwy over the years, and (very importantly) this venue decision was taken prior to the R&A/LGU merger: there is a general expectation that this will be the last time the Curtis Cup will ever go to a modest club like Conwy, and I doubt if there has ever been such a subscription discrepancy as between Conwy and its successor venue Merion! Current local subs at Conwy are well below a thousand bucks per annum...
The Llandudno area is very well placed for accommodation, and with easy access to the population centres that (e.g) flock to Hoylake championships: the contrast at present with Harlech (roughly forty miles south of Conwy) where there is currently no substantial hotel, and a local economy that was pretty bleak even before the current crisis, is massive, whatever the relative merits of the two golf courses (and RStD has been historically a regular LGU venue, stretching back to 1926).
Royal Porthcawl hosted the Curtis Cup in 1964, but the other Welsh course used by the LGU in the past for the Cup will, I suspect, amaze GCA readers: St Pierre (Chepstow) in 1980. Conwy will make a cracking venue, now in 2021, with a unique atmosphere of its own: I am also allowed to dream of the day when either the Curtis or Walker Cups makes it to Harlech, but as things stand that is just not going to happen.