A while back there was a good thread discussing the differences between distance offshore cruisers and coastal cruising boats. I suggest that you do a search on that thread.
Generally, long distance offshore cruisers make very poor coastal cruisers, but they will work if you don't mind the compromises.
And by the same token, really good coastal cruisers make really very mediocre offshore boats, but most quality coastal cruisers are capable of making offshore passages.
When you talk about Beneteau Idyle, or Oceanis, or number serioes boats, the construction lacks the kind of robustness to stand up to the kind of repetative abuse that is a part of making an offshore passage and they lack the kind of interior layouts that are optimzed for life aboard during offshore passage making.
"normally well equipped compared to before there was roller furling?"
If by this you are suggesting that in-mast furling somehow changes the equation, I respectfully suggest that for distance voyaging you want a reliable reefing system that allows you reduce sail quickly to a heavy weather size and shape. In-mast furling does not permit the kind of sail shape control that becomes important for offshore work and in talking to delivery skippers who have had a lot of experience with these systems, the robustness and reliablility and sail shape control just is not present with in mast furling.