We all have different needs & I will eventually add solar.
But…
-Thee’s a reason Tesla Walls are selling for big bucks.
-Because solar doesn’t provide capacity in the dark when people want light, power, charge and run all sorts of things. Without substantial battery power at night, solar is just a dead piece of tech that sits idle at night.
Solar is great in bright, direct sunlight…but that’s when most of us drive and don’t need it).
After the ling drive and through the night, we charge, light things up, run various equipment, or keep stuff frozen in hot weather…on battery.
If traveling, and you have to park in a structure…or under sunlight obstructions of various kinds in a forest, valley or urban…solar doesn’t power anything.
If, on the other hand, you drive all night…
…and sit around all day? Solar is perfect. -But most travelers do the opposite.
I agree that most may not see huge benefit from dual batteries. But some of us truly do.