That is the stuff you want you can add extra perlite for more drainage but I like it the way it comes holds water well it didn’t evaporate too fast allowing for the plant to use most of the water instead of going into the air and leaving extra salts in the substrate, the mycorrhiza also help big with both the growtof roots and making more nutrients available at the rates the plant is asking for it they have a symbiotic relationship with plant roots the feed off the carbohydrates the plant expels and in turn act as almost like a second root system finding and delivering the water and nutrients to the roots even when the tips can’t reach this along with a healthy Ryzoshpere also wards off pesky fungi in the garden like root rot as the beneficial fungi have taken the vacancy
A bit of Microbiology to help you out
Happy roots= big healthy plants
A botanist once told me and I love thinking of it this way is that you’re plant is just a representation of the health and vigor of the roots below