Please explain, not quite following.
Depends on the size of the inverter.
If the inverter is >2000 watts I suggest 24 volts system and a buck converter to supply the legacy electrics.
Unless they have high draw loads like jacks and/or levelers.
Then the decision is not so cut and dried.
Answering the first part, alternators are basically current limited, not power limited (pulley and belt size not withstanding) so if you have an alternator that can produce 100A continuously, the higher you set your voltage regulator, the more charging power you generate from your alternator.
As for large inverters with low input voltages, I would concede that there are safety issues associated with trying to extinguish an arc when a fuse blows as well as heating concerns if you have corrosion on one of your terminals, or a cable works loose. But I don’t see those as deal breakers.
Assuming you have a good crimper, torque all your fasteners, and use high quality fuses/breakers, the safety concerns with a 12v system can be managed.
On my RV nearly all my loads outside the AC and microwave are 12v. I’ve got a power management device that turns off the AC when the microwave is running so I don’t need a massive inverter pulling 250A. If I did need to run more than 2kw on a 12v system, I would likely install multiple inverters.
In my current RV, any wiring costs I might save going to a 24v system would be offset by having to include buck converters for all my DC loads. And since inverter standby power is generally a function of current, higher voltage inverters also have a higher baseline power draw which can be critical when boonfocking.
My next RV build won’t be an upgraded commercial RV but will instead be built from scratch and have a higher voltage system. I will install a second alternator at 24 or 48 volts so I can get additional charging while on the road and can eliminate the need for a generator.
I love desert camping where you never see a shadow or get any shading on your solar panels but I equally love boondocking in forested areas of Canada where the sun is low, the trees are tall, and outside of a few weeks in July and August, flat mounted solar on the roof is inadequate.