I actually don't dislike Atwood and even though there are issues one might take up with The Handmaid's Tale, at least that book occupies a certain place in literary history, it is an interesting and perhaps necessary look at a theocratic dystopia representing (in Atwood's opinion) the ultimate totalitarianism of patriarchy.
I found The Testaments to break no new ground in that regard; the timing of the novel was also suspicious. Coming directly on the heels of the successful Hulu show, it was obviously a cash-grabbing attempt on the part of the author. Which is fine with me, I don't begrudge Atwood the money, in fact I want writers to be financially successful (otherwise toiling in obscurity for no reward at all is just... horrible), but contrariwise it doesn't mean that the book suddenly deserves any of the literary accolades that were suddenly heaped upon it by the (no doubt) well-meaning public.
Did The Testaments deserve to be a best-seller? Yes, clearly, since people were buying it, people were reading it, people were interested in investing their time in it. Did it deserve to win prizes is another question entirely, and my answer to that is no, because the book is structurally problematic, breaks no new ground in the dystopian genre, the writing is loose (in places almost lazy), and afterwards you are left with the feeling that the whole thing was rushed (by Atwood, by her agent, by her publisher, who knows) to take advantage, while the interest in the Hulu show still lingers, of the public demand for more Gilead material.
Additionally, I realize that book prizes are individually guided by the particular selection of chairs/judges for that specific year, but it was beyond ridiculous that out of all the books published in English that year, many of which were better written, better constructed, and offered much more in terms of literary originality, the prize (in this case, Booker) finally went to one of the most lackluster books on the longlist. I wasn't a big fan of Evaristo's book either, in fact, I thought it was laugh-out-loud BAD in places, but at least it had vitality.
Again, I stress the fact that I have nothing against Atwood as an author in general: The Blind Assassin is one of my favorite books! I just had an extremely allergic reaction to The Testaments, but who knows, perhaps I will reread it in ten years' time and change my opinion: perhaps there's more to it than I was able to see after the first (admittedly, hasty) reading.