There is nothing special about Sol-Arks Inversion process, it is the same one that is used by just about every high frequency Inverter on the Market.
Actually its ( Sol-Ark and its cousins ) are "special", even in the US most split-phase storage inverters are single-phase, such as Solis, Goodwe, StoreEdge, Generac and Enphase off the top of my head that use auto-transformers for neutral requirements aka split phase..
Also the concept that older designs handle surge better isn't the just the output transformer. they were designed to meet code requirements that required galvanic isolation at that time ( XW started devolvement in 2003 ), and XW was designed component wise to handle long duration high power over 24/7 ratings. Just check out the rows and rows of caps and mosfets, then look at what is done now.
The current crop of AIO inverters
are great values no doubt and I own a pair ( Solis ), but they are NOT a good option if it is your only power source 24/7. If your off-grid and the AIO takes a dump, your out of power and likely don't have a plan for the 4-6 weeks it will likely take to get back up and running. The XW and it's generation, understand the application and yes, you have parts for different functional needs.
Charge controllers, usually a bunch of them handle the Solar to Battery, inverters, battery to loads, multiple and isolation battery banks as examples. Yes, it is allot more installation work to do this, yes it costs more, but guess what, you can have failures ( and everything fails at some point ) and still have partial harvest or power. Try being off-grid and can't get water, lose heat as examples.
As for opinions on YouTube, installers can't be an expert in everything, there are experts in XW, the aren't cheap to hire, but they can fix just about anything and know the systems inside and out and have direct contacts to engineering.
Installers that have got into the RE business with gridtie likely don't have the training or experience for whole home power plants. I'm not faulting anyone, running a business is expensive and hard, the point is their equipment preferences are likely limited to their resources, not the capabilities of the equipment on the market.
For what it is worth, even with my experience, it can be difficult to choose as everything is a compromise!