Appium/WDA v2.32.0 got rid of carthage. Then, M1 mac also was able to build it without any issues. So, I compared build speed between Intel and M1 machines.
Command
xcodebuild build-for-testing -scheme WebDriverAgentRunner -target WebDriverAgentRunner -destination 'generic/platform=iOS' CODE_SIGNING_ALLOWED=NO -derivedDataPath tmpDir
Result
M1 macOS
MacBook Air (M1, 2020)
OS: 11.0.1(20B29
Processor: Apple M1
Memory: 8 GB
Result: 2.48s user 0.96s system 30% cpu 11.101 total
Intel macOS
MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports)
OS: 10.15.7 (19H15)
Processor: 3.3 GHz Dual-Core Intel Core i7
Memory: 16 GB 2133 MHz LPDDR3
Result: user 1.88s system 20% cpu 29.091 total
Wow, M1 was almost three times faster than Intel one. The Intel one is old to compare, probably, but it was not so low spec. M1 could be a good build machine 🙂