Flavor from the maillard reaction is considered very desirable, it's why we barbecue or fry rather than poach burgers, so browning the meat is "better". I have tried it both ways with a bolognese and chili, the flavor from the browning when it is done right is noticeable and my tasters all preferred it to the non-browned product.
However, it's challenging to do that when making bolognese, I had to use a separate pan, browning the meat in batches, which was extra work and mess. It was enough work that I rarely do it that way.
Instead I do a hybrid method where I sweat the vegetables, then I push them to the side, crank up the heat and add one pack of the ground meat as a slab, smushing it out a bit to maximize surface area. After it gets a bit browned on one side I'll flip the meat to do the other side until browned, then add all the meat and sweat it all together. That way I get some browned flavor in there without that much extra work.