Our Whirlpool dishwasher wasn't draining. The filters weren't plugged. The water pump worked fine. All the typical suggested things to do, didn't work. I discovered that it was a drain hose check valve that was stuck.
Here is an Amazon affiliate link for a universal replacement hose with e check valve. You may want to verify your specific model. https://amzn.to/3sEWX3K
A stuck drain hose check valve might be the reason your dishwasher won't drain! It was for me.