Some thoughts from England on this subject.
Bearing in mind that Proofs are supposed to be a perfect example of the art of minting, I find them quite acceptable. However, I have some reservations about them.
Proofs are usually made from specially produced dies, and therefore there are subtle differences between them and equivalent circulation issues. In this case, my choice is for the real (circulation) coin, if possible before it has had much use if it is a modern coin. British Proofs now have a frosted relief, which in itself makes them unlike circulation issues.
Our
Royal Mint now has an additional grade that they issue for collectors, called "Brilliant Uncirculated". This is what it says, a coin which is highly polished and only handled/packaged under controlled conditions to prevent damage. Being so bright, they do not appear natural.
Perhaps the difference today is the marketing policy - sell - sell - sell. Whoever the customer might be, just get the money. Present day prices are exorbitant compared with a few years ago. Proofs used to be produced for the true numismatist; nowadays they are aimed at an unsuspecting public. As for NCLT in general, I'm not very amused as to me, quoted from the Oxford Online Dictionary, a coin is "a flat disc or piece of metal with an official stamp, used as money" - note the used as money!
Now to "year sets". Unfortunately, as they are produced at the beginning of the year (and now before Christmas), they are usually incomplete. Therefore, to obtain a full set of ALL coins for a year, some have to be in individual packs.
I think that, from the above, you will see that I consider sets and other specially marketed issues poor value and their distribution poorly organised.

What do we, true collectors, really want? My choice would be for, at the end of each year, a full set of all coins that entered circulation, to Uncirculated standard.
Bill.