Russian invasion of Ukraine

Not really sure what talking to him has achieved to date.

True, it's not been much use so far, but in a much longer time frame transcripts of these conversations might prove quite useful.

If we get a chance to establish a legal case in the future, either in an international court against Russia as a whole or in the very least against captured Russian officers in a Ukrainian court, near daily ramblings from the man at the top could be useful in establishing who knew what and when.
And then there is the academic bit. We're still widely studying WW2 academically, imagine how useful it would have been if we had transcripts of regular conversations between Hitler and, let's say, the Canadian prime minister at the time.

And we might as well have pretty boy Macron do the deed. He's got plenty of experience tending to the needs of people significantly older than himself.