Before reading about my choices, take the quizz yourself, it is very interesting to see how the masses have chosen.
My choice is as follows (with 1 drop first and 5 drop last):
Dropping Facebook would be pretty easy for me: I don't use their services. None. I don't think that I would notice it (despite the outcry in the media) when they would disappear tomorrow. It is even worse: I think Facebook is a threat to the open web and therefore I actively avoid it.
Dropping Microsoft is very easy for me as well: I don't use any Microsoft products, and I would not be unhappy if they disappear. Even at work we don't use Microsoft.
Dropping Alphabet would be not so easy for me. I use the Google search on a daily basis and at work we use Gmail. I would be able to replace these services (e.g. by using our own mail server at work, and by using alternative web search engines like DuckDuckGo), but it would be painful.
I use the iPhone and a Macbook every day. It would be hard to replace the iPhone, but since Google would be gone as well (see above) nobody would own a smartphone anyways, so this might not bother that much 😜 I could use Linux again, I did this for my private computer, but both would be painful.
Dropping Amazon would be the hardest for me. I use their shop very often (oh it saves me so much time), I use Amazon Prime Video for streaming and we use a Amazon Fire TV stick for streaming.