Maybe think again. You have to have an Instagram account to sign in to Threads. If you then decide you want to cancel your Threads account, the Facebook/Threads/Instagram umbrella corporation will only allow you to do this if you also cancel your Instagram account.
In addition, as both Jack Dorsey and Elon Musk have noted, signing up to Threads demands access to almost every aspect of your life. Everything you post, no matter how private, and all the data gatherable from that post; where you are, who you are with, health, financial, and family information, is Meta’s, and Meta can do with that information whatever it likes.
Finally, straight out of the block, Threads is implementing Meta’s practise of censoring and ultimately cancelling people who post ideas with which it disagrees. That’s great if you agree with Meta and prefer to live in an echo chamber. For those who are happy with diversity, happy to engage, and live in the real world, not so good.