Hi. I'm not sure whether you'll make a significant gain in versatility from such a switch. I can praise the Fuji glass from personal experience as I was an early adopter of the GFX 50S. I can't speak to the Hasselblad V series lenses as I use the H series but I note that there is a wide variety of adapters to allow you to use them on the GFX models. I have been staggered by the quality of the sensor on the GFX 50S and have also shot a couple of piccies with the larger 100S and was blown away. I use Zeiss lenses for the Contax 645 on my GFX via the Fringer AF Adapter to fill in the current gaps in the Fuji range of lenses. I suspect that using your existing lenses, the IQ won't quite match that of the Fuji glass (they also make the lenses for the 'Blad H-series), and that your current digital back will be more forgiving than the sensor on any of the Fujis. For work of the highest quality, such as recording art works or documents, I still prefer to use the Contax 645, Zeiss glass and my old Hasselblad Ixpress 528C back in multi-shot mode; each photo produces a 528Mb file with astonishing detail. However, I suspect the GFX 100S and Fuji glass would actually be a match, perhaps more than a match.
In summary, the Fuji is likely to highlight any minor shortcomings in the Hasselblad glass but if you switch completely, you certainly won't be disappointed. However, it seems to me that you have a perfectly adequate system already - and a wider variety of lenses from which to choose than can currently be offered by Fuji. However, if you ever decided to extend the nature of your photography, then the Fuji can offer something that is way beyond the scope of the Hasselblad V-series bodies: fast shutter speeds of up to 1/4000s.
My suggestion, for what it may be worth, would be to find a top retailer, take your 'Blad along and try it against one of the Fujis with a similar lens. You might also check YouTube for I think there are some videos on their platform which feature your types of lenses being used on GFX cameras. It's a major investment if you decide to switch so the more research you can do the better. Nothing beats being able to try the gear - who knows, you might not like the ergonomics...