While the hardware is a a bit underpowered, the main problem is your OS 10.8.5. The system requirements for AC 21 are OS 10.11 and above, with OS 10.10 likely to work - and OS 10.9 and earlier incompatible:
https://www.graphisoft.com/support/system_requirements/AC21/
Your MacBook Pro should be able to run El Capitan / 10.11.
https://support.apple.com/en-us/HT206886
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
One of the forum moderators
