Starting with 2022.4.X, the system started ALWAYS forgetting where you left off. Before that, by always making sure your car was awake before getting in (I always turned on my environment before going out to my car), it would pickup playback 99% of the time.
Now, what I do to get the car to remember the USB playback position is to always have Sentry active - even at home when it is parked in my locked garage. This prevents the car from falling into deep sleep and has about a 70-80% success rate of remembering the playback position. If it doesn't, THEN I use the "USB".
The shortcoming of using using the voice command is that while it picks up the song playback position, it does NOT remember where you were on the screen. In my case, I use embedded folders to organize my music (because the Tesla system sucks). With the "Sentry On" method (how it SHOULD work, without having to have Sentry on), it remembers the last folder I am. With the USB voice command, you have to start fresh in your navigation.
NOTE: having Sentry on full time WILL increase your energy consumption. I haven't done the math as I don't want to know the answer, so I can't tell you how much, but if I had to guess, it would be 7-10% efficiency hit.