The discovery of 2D materials opens up unprecedented opportunities to design new materials with specified properties. In many cases, the design guiding principle is based on one or another proximity effect, i.e., the nanoscale-penetration of electronic correlations from one material to another. In few-layer van der Waals (vdW) heterostructures the proximity regions occupy the entire system. Here, we demonstrate that the physics of magnetic and superconducting proximity effects in 2D superconductor/ferromagnet vdW heterostructures is determined by the effects of interface hybridization of the electronic spectra of both materials. The degree of hybridization can be adjusted by gating, which makes it possible to achieve a high degree of controllability of the proximity effect. In particular, we show that this allows for electrical switching of superconductivity in such structures on and off, as well as for control of the amplitude and sign of the Zeeman splitting of superconducting spectra, opening interesting opportunities for spintronics and spin caloritronics.