Is Falcon (PQ signing algorithm) slower than ECDSA in terms of computing time?

SUPERCOP is a good source of cryptographic benchmarks. For illustration, I've picked a specific CPU (Intel Skylake) and looked at the NIST level 1 (128-bit classical security) cycle counts for Curve25519, Falcon512 and Dilithium2 for good reason, at the median (50%) level. I used the AES version of Dilithium2 since it's representative of using hardware accelerated instructions for randomness.

It's worth noting that Curve25519 is the product of years of research into efficient implementations of elliptic-curve cryptography, whereas these figures for PQC schemes, if I'm not mistaken, come from the NIST submission from the designers themselves. Therefore, it is expected that this will improve over time. For instance, there's a recent paper by Thomas Pornin that significantly speeds up Falcon key generation.