What's preventing all those systems to integrate p2p payments now ? AFAIK users only need to share their wallet id, so it could be as simple as a line in the pr

What's preventing all those systems to integrate p2p payments now ? AFAIK users only need to share their wallet id, so it could be as simple as a line in the profile; when users click on a "tip this" button, the system can get the id and send some amount.