I am running into the same issue with Google Cloud IOT API on Raspberry PI 4. Tried the above commands to re-install the grpcio modules, but still not working.
File "/home/pi/.local/lib/python3.7/site-packages/google/cloud/iot_v1/__init__.py", line 17, in <module>
from .services.device_manager import DeviceManagerClient
File "/home/pi/.local/lib/python3.7/site-packages/google/cloud/iot_v1/services/device_manager/__init__.py", line 16, in <module>
from .client import DeviceManagerClient
File "/home/pi/.local/lib/python3.7/site-packages/google/cloud/iot_v1/services/device_manager/client.py", line 25, in <module>
from google.api_core import gapic_v1 # type: ignore
File "/home/pi/.local/lib/python3.7/site-packages/google/api_core/gapic_v1/__init__.py", line 16, in <module>
from google.api_core.gapic_v1 import config
File "/home/pi/.local/lib/python3.7/site-packages/google/api_core/gapic_v1/config.py", line 23, in <module>
import grpc
File "/home/pi/.local/lib/python3.7/site-packages/grpc/__init__.py", line 22, in <module>
from grpc import _compression
File "/home/pi/.local/lib/python3.7/site-packages/grpc/_compression.py", line 15, in <module>
from grpc._cython import cygrpc
ImportError: /lib/arm-linux-gnueabihf/libc.so.6: version `GLIBC_2.33' not found (required by /home/pi/.local/lib/python3.7/site-packages/grpc/_cython/cygrpc.cpython-37m-arm-linux-gnueabihf.so)