2027? There's enough time for the Bitcoin Core devs to write and implement post-quantum algorithms.
Why do you even bother?This is just another "Quantum computers will kill bitcoin!" type of topic,like many other topics here.Why to be afraid of a monster that doesn't even exist?

It doesn't exist
yet, but it's true that we should plan for it. This is what the OP said:
There are a lot of figures and formulas in the report, I haven't understood everything, but the main idea I've caught is that if Bitcoin doesn't implement post-quantum algorithms, it won't survive until 2027.
I agree we shouldn't fearmonger about it, but safely and cohesively hard forking to make the necessary changes may not be an easy feat. Any hard fork release should have a
very long activation time to minimize the possibility of a network split, so we should be talking about this sooner than later.
Given the size of the Bitcoin network and its rate of adoption, I think we should avoid emergency forks to whatever extent possible.
As what I've look a heads in coming years ahead bitcoin will be more safe and proliferate as what we had now, because of continuous development.