I think Prusa has had a couple of missteps of late, but they’re not in the gutter yet. On the XL: the 0.6mm makes sense with the build volume, to significantly improve print times, but seems to really not work well with the 5 toolhead models, and introduces massive amounts of zits, stringing, cross-contamination, etc. On the Mk4: at the price point, it’s maybe missing a few features to really hold up against the X1C,…
Marlins biggest weakness is needing to recompile for some things because they are defined by compile-time. All other things like active input shaping calibration can be added relatively easy.