Its (presumed) competitor, MIPI-CSI is not open source either.
SLVS-EC looks easier to interface with an FPGA at least, presumably the voltage levels are closer to standard, unlike MIPI D-PHY's exotic dual level switching that either requires an external IC, a passive resistor network of borderline compliance, or an FPGA (e.g. Lattice CrossLink) with the correct special inputs.
SLVS-EC has some very minor issues when interfacing (DC offset compliance) which requires a hack in detecting when the link is up. And yeah, MIPI D-PHY is a royal pain unless you have native support (Xilinx, Lattice, Intel Agilex 5). C-PHY even more so.
SLVS-EC looks easier to interface with an FPGA at least, presumably the voltage levels are closer to standard, unlike MIPI D-PHY's exotic dual level switching that either requires an external IC, a passive resistor network of borderline compliance, or an FPGA (e.g. Lattice CrossLink) with the correct special inputs.