I was recently trying to do similar in a .Net 7 Angular project and also was getting 404's despite trying everything above.
What worked for me was to put the file in the asset folder under Client App, and to specify in index.html
<link rel="icon" type="image/x-icon" href="assets/favicon.ico" />
Similiarly in nav-menu.component.html I had a logo in nav-brand that I also put in assets and referenced as below.
<img src="../assets/logo.png" height="48" />
Server side, I had Identity scaffolded, and placed my images under wwwroot/Indentity/images. And then I referenced them as below in _Layout.cshtml.
<link rel="icon" type="image/x-icon" href="/Identity/images/favicon.ico" />
<img src="/Identity/images/logo.png" height="48" />
I do feel one should be capable of making it work with files in wwwroot, but it seems this work around is a fall back.