Hi BR & welcome.
You're not the first member recently to describe an "all in one' base with all the spicing contained within it. It certainly must speed up (and maybe de-skill) the process of churning out finished curries on the night of service, perhaps helping profit margins by decreasing staff costs. But the downside must surely be they struggle to differentiate their dishes from one another?
Apart from being very thick, the base is very dark compared to most I've seen. This would seem to indicate a lot of powdered spices have been added, as I noticed the same darkening effect when following C2Go's video to try his base. I notice from your profile you're in N Wales, not too far presumably from Julian in Chorley (curry 2 go), so perhaps these heavily spiced bases are a regional variation in the North West / N Wales region?
Curry in this country is undoubtedly evolving over time - there are forum members whose primary interest is in replicating the BIR flavours of the 1980s and those recipes differed from the standard fare of today. Maybe all in one bases are part of the "new wave" which will take over? If you look at what drives this evolution of restaurant cuisine it's usually economics, with new short cuts being introduced to get the costs lower - sad but true. I'm sure that the BIR flavours of the 70s and 80s came at the price of a lot of labour being expended with many different gravies being prepared. Once it became harder to bring in immigrant chefs willing to work for pennies, the recipes evolved into the single shared base with different spicing per dish... And now maybe it's heading to an even easier next generation?
A lot of speculation on my part there, I'm not sure any of that is really the case, but I wonder if it's all driven by labour costs.