Both have their places. If you know-how, you can get definitely prove either system works better with shading. But the fact is, per panel MPPT is always going to outperform a string MPPT when the panels are properly matched to the microinverter and there is variable shading throughout the day. If you have a lot of single-edge shading you might be interested in replacing the panel's diodes with
maximizer chips if you have string or microinverters.
Enphase Microinverters are more expensive per watt than some inverters (but possibly less the Sol-Ark), but when you start adding in the MPPTs and other stuff it equalizes the price somewhat. But there are cheaper vendors that cost less than Enphase too.
IMO, Microinverters are simple and easy to install, have low roof voltage, no figuring out how to design strings for the MPPT, allow for different panels of different ages/outputs to work together without losses, usually have far longer warranties, they usually have the highest of inverter efficiencies, have the RSD built-in, give per panel diagnostics making problems easier to find, the system is easier to expand, they don't take up additional space like a string inverter does, are silent, decreased shipping costs, if one dies all the rest keep working, and yes they are worth it even if your panels don't have any shade.
They also have unique problems if you want to add a local ESS.