@hannob ECDSA is faster in terms of signing compared to RSA. This would lower the load on Let’s Encrypts HSMs. Not sure if that’s really necessary though.
Unfortunately, verification of ECDSA is much slower. P-256 verification is about comparable to 4096 bits RSA, but P-384 is more than 10 times slower. 2048 bits RSA verification is massively faster though.