Higher battery voltage == less copper, smaller wires for the same wattage. Sometimes also a bit more efficiency too (less resistance, smaller absolute voltage drop moving current around).

Your units are a bit messed up load wise - is your computer running at 1 kWh per hour? For how long? (Yeah, that is confusing - but that would be the energy used to power a 220 volt, 4.5 amp load for an hour, every hour).

One of the confusing things with some of these units is kWh is a measure of energy, even though it has a time component in the name (kWh can be directly converted to joules). It isn’t ACTUALLY a measure of power (aka energy over time), even thought it implies it is because it has ‘hour’ in the name.

Power is energy over time.

So you have an absolute number for storage (your battery in this example can store 2.1kWh of energy - 2.1kWH is equivalent in energy to 2100 watts drawn out over an hour).

Your inverters, panels, chargers, etc. will be rated for a level of output POWER (energy over time) then will draw/convert that (say 4 or 8 kw) to/from the batteries. You can easily have an inverter that can draw down those batteries super fast (say will pull down 8kw continuous, so you’d get less than 15 minutes on that battery - if it doesn’t get damaged or explode), or one that draws power out slowly (say 200 watts max) to make it last 10 hours say.

Same with your chargers, etc.

You’re solar panels are almost certainly not rated in kWh, but kw- aka maximum instantaneous power they would be producing at any moment under ideal conditions, not aggregate energy they would be producing or storing over time. This is important because they don’t store power and actual energy production will depend on a lot of factors, like amount of time in the sun, etc.