Audacity (2&3) only uses one core, even if you have more.
Because of non-destructive editing feature added to Audcaity3 it’s more CPU intensive than Audacity2, and consequently will be more sluggish on the same machine.
Audacity’s free competitor OCENaudio loads/zooms/saves faster, and it has a dual display …
ChatGPT tells me … " Yes, ocenaudio does support multi-core processors … If you’re working with very large files or complex edits, you should notice improvements in responsiveness and processing times when using ocenaudio on a multi-core CPU.".