I own both, bought few weeks apart this year. 8GB M1 is faster, cool, and quiet. Perfect mac machine. i5 is noisy and hot but allowed me to up the memory to 20GB (4 original + 16 replacement) for reasonable price and I can run Parallels with Win10 on it. It runs two OSes, 24h/day, without any issues. Major difference is heat and power - i5 routinely uses 40-60W and is hot, M1 uses few wats and is cold.
Would I replace i5 with M1 if I did not needed Windows? No, its not worth it - difference to M1 is not large enough to force upgrade for me. May be in few years with M3 or whatever next generation will be.