If it were my bike I'd either replace just the left shifter with an exact, used replacement or upgrade the drivetrain to 11 or 12 speeds. Shifters are the largest cost in the drivetrain.

I kinda like SRAM doubletap road drivetrains, although they've become rather uncommon OEM for everything but 1x bikes with disc brakes. They are entirely incompatible with Shimano rear derailleurs so take that into account.