You could use the OpenCode legacy patcher to upgrade to v15/Sequoia: https://dortania.github.io/OpenCore-Legacy-Patcher/
Also, the writing is on the wall: Ultimately, Homebrew will be ARM-only, once Apple's legacy support becomes ARM-only. At which point it's game-over for Intel Macs.
Homebrew solves the "availability of software" problem in the Mac ecosystem, but it does not solve the "Need to stay on the new hardware treadmill" problem.