Can dapps and defi be created on bitcoin or do we need ethereum?

Hi gang, pretty new to crypto but learning programming and would like to become a blockchain developer, I just listened to a Robert Kiyosaki interview with Robert Breedlove, he had rather an interesting response when asked about ethereum, and basically said layer 2 solutions dapps etc can be developed on the bitcoin blockchain, is that even a thing? I thought that was why ethereum was created.