EDIT: note that this thread is from 2018, the post is otherwise unedited
So I haven't played any ladder in almost three months and I just finished my matches for this season in the League and decided not to return for the next season. Here are some reasons why, in order from most to least important:
1) Prismata doesn't have any of the following problems and it's just a really good game in general so I'd rather spend my time playing Prismata.
2) My opponent can take a really long time to think while I have nothing to do. Slowrolling on purpose is a rare problem, but people who just take a long time to think are pretty common and just as frustrating to play against.
3) There's no deck tracker. This means I have to choose between spending a long time digging the log for information all the time and making uninformed decisions all the time.
4) Shuffle iT's implementation is sometimes very slow, which is probably at least partially because it's a browser client, not a standalone.
5) There are many reasons why the game can be a serious uphill battle for one player for reasons nobody had any control over. The most notable reason is first player advantage, but games where that happens because of shuffle luck are also common enough that they actually happen. While alternating the starting player can make it a fair match in a tournament or the League, that doesn't make it any more enjoyable to play the games where a player can only really lose if they make an enormous mistake.
6) If I play ladder actively, I mostly have to get matched against people who are significantly worse than me. This might not be true at the moment, but it was when I stopped playing ladder three months ago, hoping that the other problems wouldn't bother me so much in the more competitive and more evenly matched League setting (but as it turns out, they still did).
7) Donald X. has been talking about each new expansion being diminishing returns because you only get to see the new cards so often when there are 300 other cards in the pool, and with the release of Nocturne, I think we finally passed some kind of a threshold for me where I feel like it actually didn't really contribute very much towards making the overall game more interesting. I still have a lot of Nocturne cards that I suck at playing, and I think that's mostly just because a lot of kingdoms just have the same old cards that I can already wrap my head around and the Nocturne stuff doesn't show up all that much. This is not really even a problem per say, but some kind of a standardized format (that you could automatch for) that leaves out some of the older expansions certainly wouldn't hurt.
Honestly if Stef gets his ShiT together and does something about points 2, 3, and 4, that will probably be enough for me to get back into playing Dominion actively, but aside from that, I'll probably only play in the big tournaments and whenever there's a new expansion just to check it out.