Beer traps show you the extent of the infestation. Very unpleasant but you then know what you're up against.
Slugs follow their own, and other slug's, sticky trails so they know where the goodies are. The slugs I had were resistant to eggshells, gels, felt, sharp sand, nutshells, copper bands and various other things I tried. I did not try pellets as l have a terrorist (sic) that eats slugs (this was problematic as they are a danger to dogs).
Beer traps and midnight forages brought to light the fact that I'd never defeat them but l could deter them, to an extent, from the vegetables. It was not happy gardening. I became a tad obsessed (it was lockdown so l was quite bored).
Anyway, I moved.