I think GP is talking about dedicated winter tires, which wear quickly and have poor performance in conditions above 45F. "All-weather" tires like CC2s are designed for and must tolerate year-round use.
No -- they're still superior to all-weather tires in snow and ice. If you get a lot of that, they may be worthwhile. E.g., https://www.youtube.com/watch?v=8K8ThRGNaoM
Spreadsheet: https://docs.google.com/spreadsheets/d/1Smk69SCu5WrI3yRd_FO6...