Let me draw the members attention to the original post.
"our single deep cycle and generator work well for us. Im just curious because i see videos and read articles about folks just going crazy adding solar to their rv's. One guy spent $5000.00 on Lithium batteries alone"
Will be happy to hear the OP clarifications if I got this wrong, but... conclusions that seem obvious:
Little knowledge about how things work, how much they cost or what is needed. 5K Li is only relevant to big systems and/or if you are trying to run A/C on it. One can have a solar with the same 2*6V at $250 cost as somebody who has no solar.
Unclear energy needs (or again little knowledge about battery charging and inverters). Could be single battery with inverter and, say, 1 hour generator time because their energy needs are low. (Battery will remained undercharged then).
Or - single battery, no inverter, generator running all day or whenever they need, for example, to charge cellphone (yes, I've seen people doing this), or to watch small TV.
Or - single battery, no inverter, generator running all day because their energy needs are high.
He never explained.