Some shell hackery shows which tools have been updated to run on Apple Silicon
pushd ~/Library/Arduino15 ; diff -u <(find . -type f -perm +111 \
-exec sh -c 'file "{}" | grep -q "x86_64" && ! file "{}" | grep -q "arm64"' \; \
-exec dirname -- {} \; | sort -u
) <(find . -type f -perm +111 \
-exec sh -c 'file "{}" | grep -q "arm64"' \; \
-exec dirname -- {} \; | sort -u
) | sort -d ; popd
For example, narrowing that initial directory to ~/Library/Arduino15/packages/esp32 yields
+./tools/esp-rv32/2507/bin
+./tools/esp-rv32/2507/lib
+./tools/esp-rv32/2507/lib/bfd-plugins
+./tools/esp-rv32/2507/libexec/gcc/riscv32-esp-elf/14.2.0
+./tools/esp-rv32/2507/libexec/gcc/riscv32-esp-elf/14.2.0/install-tools
+./tools/esp-rv32/2507/libexec/gcc/riscv32-esp-elf/14.2.0/plugin
+./tools/esp-rv32/2507/lib/gcc/riscv32-esp-elf/14.2.0/plugin
+./tools/esp-rv32/2507/riscv32-esp-elf/bin
-./tools/esptool_py/4.5.1
+./tools/esptool_py/5.1.0
+./tools/esp-x32/2507/bin
+./tools/esp-x32/2507/lib
+./tools/esp-x32/2507/lib/bfd-plugins
+./tools/esp-x32/2507/libexec/gcc/xtensa-esp-elf/14.2.0
+./tools/esp-x32/2507/libexec/gcc/xtensa-esp-elf/14.2.0/install-tools
+./tools/esp-x32/2507/libexec/gcc/xtensa-esp-elf/14.2.0/plugin
+./tools/esp-x32/2507/lib/gcc/xtensa-esp-elf/14.2.0/plugin
+./tools/esp-x32/2507/xtensa-esp-elf/bin
-./tools/mklittlefs/3.0.0-gnu12-dc7f933
-./tools/mklittlefs/4.0.2-db0513a
-./tools/mkspiffs/0.2.3
+./tools/openocd-esp32/v0.12.0-esp32-20230921/bin
+./tools/openocd-esp32/v0.12.0-esp32-20250707/bin
+./tools/riscv32-esp-elf-gdb/16.3_20250913/bin
+./tools/s3-gcc/2021r2-p5/bin
+./tools/s3-gcc/2021r2-p5/lib
+./tools/s3-gcc/2021r2-p5/libexec/gcc/xtensa-esp32s3-elf/8.4.0
+./tools/s3-gcc/2021r2-p5/libexec/gcc/xtensa-esp32s3-elf/8.4.0/install-tools
+./tools/s3-gcc/2021r2-p5/libexec/gcc/xtensa-esp32s3-elf/8.4.0/plugin
+./tools/s3-gcc/2021r2-p5/lib/gcc/xtensa-esp32s3-elf/8.4.0/plugin
+./tools/s3-gcc/2021r2-p5/xtensa-esp32s3-elf/bin
+./tools/xtensa-esp-elf-gdb/11.2_20220823/bin
+./tools/xtensa-esp-elf-gdb/11.2_20220823/lib
+./tools/xtensa-esp-elf-gdb/16.3_20250913/bin
+./tools/xtensa-esp-elf-gdb/16.3_20250913/lib
So version 4.5.1 of esptool_py is Intel, requiring Rosetta, but 5.1.0 has been updated to Apple Silicon; as has most of the toolchain.
Almost everything in packages/arduino still requires Rosetta. For packages/builtin
-./packages/builtin/tools/ctags/5.8-arduino11
+./packages/builtin/tools/dfu-discovery/0.1.2
+./packages/builtin/tools/mdns-discovery/1.0.12
+./packages/builtin/tools/mdns-discovery/1.0.9
+./packages/builtin/tools/serial-discovery/1.4.1
+./packages/builtin/tools/serial-discovery/1.4.3
+./packages/builtin/tools/serial-monitor/0.14.1
+./packages/builtin/tools/serial-monitor/0.15.0
only ctags (I have IDE 2.3.6 on this box)