Why does Kaspa use proof of work instead of proof of stake like some other DAG coins?

Kaspa uses proof of work because it is built as a generalization of the Nakamoto consensus — the same security model that underpins Bitcoin — whereas many other DAG-based projects use proof of stake, which has its own problems. Proof of work means miners compete by expending real computational energy to add blocks, and this is what allows Kaspa's security to be proven mathematically in the same way Bitcoin's is. Proof of stake, by contrast, relies on validators locking up coins rather than energy, and the source notes that approach comes with its own unresolved issues. For a beginner, the key takeaway is that Kaspa's choice of proof of work is a deliberate design decision tied directly to its goal of being provably secure.