That is the entire point here. iPhones are no longer "unserviceable". They are selling the parts so you can service it yourself.
What exactly is your complaint? That they are not as easy to service as your old flip phone? The modern iPhone has more computational power and technology packed into it than a full size desktop computer from 3 years ago. Modern phones are so much more than just a phone and will never be as easy to service as your old flip phone. No tech company will ever satisfy your complaint if that is what you truly desire.
I don't see why battery life is relevant to phone size. My point was just that I don't mind a bigger phone. It doesn't matter to me. We got to the point that they were thin enough long ago. If they could add a few millimeters of thickness and have a phone with a battery that lasted 30 or 40 hours that would be preferable to me. Instead manufactures are obsessed with making thinner and thinner phones.
As for waterproofing I have never in my entire life ruined a phone by dropping it into water. I would still prefer removable batteries. It is a good trade-off in my opinion.
I am willing to concede that my opinions might not reflect those of the general public.
https://www.apple.com/iphone-13-pro/specs/
Also the new iphones are waterproof, your old phone was not.