If Lee Sedol says "Okay AlphaGo, let's play!" and sits down at a board what happens? Nothing happens! AlphaGo has no agency. AlphaGo is an extension of human agency. AlphaGo isn't better than humans at Go. Humans with AlphaGo are better at Go than humans without AlphaGo.
AI is the future of Go because it enables those new perspectives and new processes by which human players can learn. AI is smart-dumb, looking for patterns beyond the human capacity, but limited by the data on existing human players that has been provided to them.
Strava hasn't made running races pointless. I can compare my runs to others but that is a very different metric then beating them in a head to head race.
Except it isn't. In various games, new strategies have been found by playing AI vs AI. It's also possible to create AI players by self-play with no knowledge of human matches.
What makes recent breakthroughs in AI agents playing adversarial games possible is the fact that deep neural networks are able to develop patterns that yield short- and long-term strategic planning. And the ability to self train without human intervention to reach unprecedented training levels.
I think you misunderstand how AI in games like go now works. Most of the advancements recently have been from the AI playing itself, oftentimes without any database of human moves at all.
But the ability to play Go never matters outside of playing Go, and we know who is the best at playing Go.