I just got the 2023 MBP 16" (base model) and honestly I'm insanely impressed with the battery life. I work in the living room from about 8am to 6pm and have ended the day with ~20% battery life. So when they say all day battery life they aren't kidding.
Obviously if I'm on non-stop zoom meetings or doing more intensive stuff it might not last, but so far its been impressive.
There will always be a new one. If you want to stay on the latest just sell your current one when the new one is released you'll get a good chunk of it back.