Unfortunately, The XPS would be useless for that part of my workstation class problems that target the Apple ecosystem.
Like almost everyone, I'm financially constrained as well as space constrained. so buying multiple expensive machines, or a high end Mac Pro or something is not on the table as an option.
So it's a compromise.
My compromise at the moment is to use a MBP for Apple things, do smaller Linux and Windows things in a VM on it, and do big Linux and Windows things on cost-optimised rented servers much more powerful than the XPS from Dell. That seems to be a better use of the resources I have for the workstation class problems I'm choosing to solve.
An additional target of my interests is the M1-class processor with it's ARM plus extensions architecture.
So I will wait and see what the next high end, ARM-based MBP from Apple is like. By all accounts the M1 is an excellent and powerful processor, competitive with other Intel-based laptops, so its successor may be a good match for my needs. It might not be, in which case I will need to revisit my strategy, but until it's announced we don't know, and it doesn't make sense to buy an XPS at the moment for what might be just a few months of only marginal discomfort. I have my servers after all.