AirPods 4 are uncomfortable due to their larger size

Returning them if within the 14 days given to decide if they are going to work for you, and purchase the AirPods Pro that has adjustable tips to accommodate many different ear shapes.

You can also send feedback to Apple here:

Feedback - AirPods - Apple

There is no one size fits all device that fits inside of everyone's ears. All that can be done is to have a device that will fit the largest number of users comfortably. The return policy is used to determine if you are one of those users.

If you purchased them directly from Apple, you have 14 days to return them for a refund. Otherwise, ask the retailer where you got them what their return policy is.

It's impossible to produce earbuds that will be comfortable for everyone.

There's not much you can do with the non-pro AirPods to make them more comfortable. You could sell them and buy something that works better for you.