Awesome. Outside of a few strange political situations like HK/Singapore we probably don't actually need to build structures higher than 12-18 stories as well - most examples I can think of are vanity projects.
It strikes me that there might not be a replacement for concrete in other forms of building though - what about dams, bridges, etc?
Cross-Laminated timber or CLT.
https://en.m.wikipedia.org/wiki/Cross-laminated_timber
12 and 18 storey structures have been built.
As far as fires go, yes, they will burn eventually, but they won’t weaken as quickly as steel. You get more time to evacuate.