@Lemonmoon, nothing that you will read on Dave's Garden or on any other gardening site (including this one) or that anyone on this site can tell you can replace this basic fact: There is no 'one size fits all' potting mix for every plant.
Each plant needs to be addressed separately and the thought process that should go into the selection of your potting materials should vary plant by plant.
The plants you have decided to start with aren't very exotic in their requirements. All of these grow here for me planted in the ground in nothing but our native sand. But for houseplant culture, you should look into where your plants actually come from naturally and try and duplicate what they have in the wild.
Monstera and Epipremnum aureum and like weeds in nature. The epipremnum will grow practically anywhere, even in the salty sand at the beach. Monsteras are hemiepiphytes. They will grow in soil, with no soil as an epiphyte, and can also grow in nature in wet areas that are almost bog like.
When you say 'elephant ear', you need to be more specific. Alocasia? Colocasia? Xanthosoma? Those are the 3 most common 'elephant ears' besides Caladiums that are sold for houseplants. For Alocasia, your choices should be tailored to the actual type or species. Colocasias and Xanthosomas are, again, like weeds. They will grow in dirt, in a bog, or in a pond.
Marantas come from the deepest darkest reaches of the rainforest floor where the soil is a loam made up of decayed plant material.
Rubber trees are standard terrestrials.
I have a plant collection of approaching 2500 plants that I have collected over theist 35+ years. None of them are houseplants, they either grow out in the yard or in a greenhouse. I don't use any special mix for anything except my aroids, and then, the choice of substrate is made according to how the plant grows naturally in the wild. Terrestrial, epiphyte; lithophyte; hens-epiphyte. Bot for most except the lithophytes, the ABG mix is a great mix
