Logged in the AmEx app and checked Offers for my Explorer card, AmEx describes it as taking advantage of this great rate for your new purchases for the 'holiday season', larger purchases you've been thinking of or simply your everyday essentials.
Whether it makes sense to pay any interest at all ever (it probably doesn't), is up to you to decide.
Edited to note that waiting further may produce a new offer with a lower interest rate - there are certainly very rare cases when it might make sense, and for those cases, having knowledge of the offer may work out better than not knowing of it - hence my sharing it.
Got this about 3 months ago on my Velocity Escape card. 3.99% for 6 months.