Web P2P/WebRTC: is it possible to signal successfully with one-way data transmission? (e.g. A to B?)

My goal is to create a p2p serverless web application and I'm not completely clear on the possibilities yet. I figured there was a need for peer discovery and that there would be NAT issues. After that, I searched on Google and read a lot of articles, I came to the conclusion that WebRTC is my only bet. However, there is a thing that I don't understand:

Why is it not possible to create a p2p connection through simply sending a sharable link with connection info in the GET parameters of the URL? If Alice sends her public IP (and whatever else) to Bob via example.com/?info=<IP_ADDRESS>&info2=<OTHER_STUFF>, then why can't Bob immediately connect to Alice? Why does Bob need to offer a response?

I know that it is possible if Alice sends her data and Bobs sends his, but I want to know if it is possible if only Alice sends her data. I don't want to use a signalling server if I can solve p2p via a shareable URL.

This answer seems to suggest it's not possible: Establishing WebRTC peer connection

Is it possible with any technology (i.e. not only WebRTC) to create a p2p application in which only Alice sends her info and Bob can respond back to Alice by using her IP-address?

In this question you may assume that NAT is not an issue/is solved via STUN/TURN servers before Alice sends her information over to Bob.