It's kind of difficult to do any kind of perfect comparison because there are so many ways to measure performance.
Intel's Core iX series has been quite a good performer over the years. However, they're in maybe the 10th generation and there have definitely been improvements. Definitely don't rely on clock speed to be your only consideration. Benchmarks are a crude means to judge performance, but they do give an idea of how newer processors perform.
https://browser.geekbench.com/mac-benchmarks
https://browser.geekbench.com/macs/364
There doesn't seem to be any score for the 2020 MBA since it hasn't officially been released, although I've heard of pre-release samples being evaluated by reviewers. The latest MacBook Air model I see in their database is the late 2018, and it's slightly better in the Geekbench 5 benchmark than the late 2014 MBP.
https://browser.geekbench.com/macs/437