(I have no affiliation, just a fan)
The sad thing is that it definitely could be. If you install Bitwarden (an Electron based password manager) from the Arch user repos, Electron is a separate dependency shared with other Electron applications. This means Bitwarden itself can be downloaded in just 5.4 MB (compressed, of course).
Tauri is not that different, though its dependency is the system browser rather than the Electron framework itself. I think Tauri's approach is better, but a lot of Electron applications could be only a few megabytes in size if dependency management wasn't done so badly in modern software distribution.
Unsurprisingly, the Linux AppImage is 87MB in size because it comes with a runtime. There's a smaller (17MB) .deb file, but I don't see any references to a package repository, so I guess on Debian based systems it'll just make you download the .deb every time to install it manually.