I agree that the difference is massive. I used to get around 18 hours for standard productivity tasks and web browsing. With the same usage on my new 14" MacBook Pro I get around 12 hours max. Now the question that everybody should answer for him/herself is, do you need the extra battery life? Do you think that the new features (Display, speakers) and the much better performance are worth it? I answered these questions with yes and I couldn't be happier. The new MacBook Pro lasts me though a full day and has juice available for the evening. It offers all day battery life. The 13" MacBook Pro offers a two days battery life. That is basically the difference. I would go on a weekend trip with my 13" MBP without taking the charger, but with the 14" I would always take the charger with me. Is it a big deal? For me no.Because it is not even matching the specs bro. I am getting MAYBE 7-8 hours on 14", whereas I am legit getting like 20 hours on the 13" some days. It's a massive difference.
I enjoy the great display, speakers and the Retina resolution. I don't miss my M1 13" MacBook Pro.