Typically, low interest rates are enough to really incentivize buyers, and it's still a key ingredient to the frenzy we have seen - but it's not everything. Attractive interest rates don't help if someone has lost bidding war after bidding war. As I write this, the Federal Reserve released this announcement:
"In light of those expectations, the committee voted unanimously to keep short-term rates anchored near zero. However, a majority of members now see the first rate hike happening in 2022. In June, when members last released their economic projections, a slight majority put that increase into 2023."