It doesn't have to, they can still cancel after s2 or s3.I wonder if it will come to bite them back, especially once people realise that it's meant to focus on the siblings rather than one solid couple
This is not a guarantee that the seasons will happen, but it is some peace of mind for fans in so far that you don't have to fret after every season whether a renewal is forthcoming.
And cancellations after multi-renewals like these don't happen often, it's more like: we'll do this many seasons for sure if viewership is strong.
Yes and I also hate esp in American TV the forced drama amongst long running couples and characters, it's why I stopped watching some US shows when they run for too long (looking at you, Grey's!).I think that a lot more people have also read the books after seeing the series, so they now realise its not just about Daphne and the Duke. If I'm honest I'm looking more forward to all the siblings stories being developed too, rather than just focusing on one couple
This way, you can have drama, but not compromise character development and much else, which is so common in long running US TV programs.