make android work as if it's a real physical USB drive

It would be cool to make android behave as if it's a real USB drive when connecting the device to TV and PC(s). So we don't get things like "Unsupported" and make many things possible. I tried doing some diggings and found it was pretty easy in older versions of Android according to this xda post due to USB mass storage. Since it was possible to emulate as USB drive, I'm sure it still is possible now. **In Android 4.4 I found a structure sys>devices>virtual>android_usb>android0>f_mass_storage. My guess is, this can be used for emulating USB drive(guess cause, I'm a total newbie yet to firefup Android studio and write code on it). But I can't find this structure on Android 10(f_mass_storage is missing). Is there there something like this in Android 10 or any workaround with it in Android 10? **mount my system file. Create a block device mmcblk1(not sure if I used the right term, like /dev/sda in Linux). Format it with USB alike file type( like /dev/sda1 in Linux ). And somehow direct to this location when a USB cable is connected to a TV or etc throught an app. Also do I have build a USB drive protocal here instead of Android default protocol?, it's kinda getting messy..... Am I with a wrong concept to pull this off? If yes, any advice how to do it? Also any reference/article related to it would be much appreciated (as mentioned, total newbie :/ )