Anything that did that much munching is not some tiny insect or even a bunch of tiny insects and instead a larger critter. Damage like that normally comes from things like caterpillars, cutworms, cabbageworms, etc. If you have something like that you will normally find it not far from where it has been eating and be hanging on under a branch or on a branch or under a leaf or on the main stem. Color-wise some will blend in very well and not be all that easy to see and some will be darker and more mottled or spotted and be easier to see.
Look your plant(s) over very closely and you are likely to find something along the lines of one of the types of critters I mentioned.
It could even be slugs. They will normally hide during the day/when lights are on, in loose soil/mulch etc. and then come out at night/when the lights are off and munch.
That makes them more difficult to spot because they won't hang out near the area they have been feeding on.
If you have a garden supply store where you can purchase preying mantis, or can purchase them online, you can get a few and put them on your plants and they will wipe out the sort of critters I mentioned. They are like the great white sharks of the insect world, they are voracious eaters, and they will not miss any larger critter like that and they will remain on the plants for as long as there is a food source for them to live off of.
For smaller tiny critters like spider mites lady bugs will do the job. They are also voracious eaters and they will wipe them out. There are also predator mites that are not harmful to plants that will wipe out spider mites and similar tiny critters.