Bike Trailer + More Batteries = Long Range (E)Bike?

Hi Forum, this is my first post!

I was reading on here about creating DIY EV cars or another site and they said if you add more batteries, you increase range. I didn't see much online about adding extra batteries to an ebike to improve range, and could not find any pages arguing for putting some extra batteries in a bike trailer to dramatically increase range. The range of a lot of ebikes looks like 10-50 miles, which honestly to me seems small and like you might as well just physically bike the extra mileage than rely on electric assist (in fact a lot of cyclists seem to argue for that). If someone wanted to ride a "century" (100 miles) or double century (200 miles) on a (e)bike, how would they go about making that happen?

If you put extra batteries in to a trailer and hook them up to an ebike, could that help to get you to a 200 mile range? How can a long range ebike be created? Should such a bike also have a motor on one of the trailer wheels, and should they be activated along with the bike, or separately (like, you could run out the battery on a trailer wheel motor, then run the batteries out tied to the ebike, or should you have both motors running at once?). Would you want motors on both wheels of a trailer and/or both wheels of the bike, or should you choose one side or the other of the trailer, or front or rear of the bike to have a motor on it?

Will you need stronger motors on both because the bike is heavier now?

Should a cargo bike be used that is a bit heavier?

Does this kind of design get too heavy at some point where pedaling becomes useless and you need to just switch to an EV-motorcycle? (Is this why I don't see designs online that add extra batteries to a trailer, or has it just not been done much yet?)

I appreciate any thoughts on this topic, I thought an ebike would be able to travel further for less than an EV-car or EV-motorcycle as it is lighter, so I was kind of thinking how an EV-car's electrical design could be adapted to an ebike for longer range.