Personally with all version (stable, beta, dev, canary) it start with superspeed i thinks there is a culprit who slow down your computer (another services who need to be launched or so), but i have seen that edge canary do some experiments to improve the launch speed on slower computer (startup booster they call that) :
https://www.ghacks.net/2020/10/24/microsoft-is-testing-a-startup-booster-for-its-edge-browser/

edgesuggestions

Iron Contributor

Oct 25, 2020

Wittycat again, is not the launch speed but the first launch speed (see comment before). this makes a lot of difference.

PS: edge and chrome don't have the same problem like safari, where i can confirm "more extension or app you have, then the start is simply slow" (maybe even 3+ minutes), no matter which mac, macos, or safari version. i can use 500 extensions or 1 extension, with chrome/edge the launch is always the same, or at least similar.