I think its 50/50 benefitted in both sides. However, with or without DeFi Bitcoin will remain as the largest cryptocurrency in the market. The trend and popularity will continuously spreading all around the world as many people are trusting it, unlike DeFi which has a new existence to people and I absolutely have doubts with their projects.
^ Every time when there is a project Defi hype there will be a purchase of bitcoin in the market since these Defi projects need to purchase ethereum or bitcoin to invest in Defi token projects. So, I think there could be a huge impact in bitcoin price not only bitcoin or the entire market that can able to use to invest Defi token/projects. Nevertheless, if the scam projects of Defi will continue, this also has a negative side effect to the bitcoin since they are not a bitcoin holder.