Is your cat doing this out of boredom, for play, or because the cables move and look like prey? The answer changes the strategy a bit.
Either way, yes, it's genuinely dangerous. He can get shocked, burn his mouth or tongue, and damage appliances too. But there are some pretty simple solutions that don't involve tape everywhere. Try offering alternatives first: toys he can bite to his heart's content, like rubber or rope ones. A bored cat bites everything in sight, so spend time playing with him every day if you can, preferably with a laser or those wand toys with feathers on the end. As for the cables, you can coat them with strong dish soap (the concentrated kind) or clove oil in the spots where he loves to bite - most cats hate it. You can also cover them with foam tubing or those plastic cable trays you get at hardware stores; it's discreet and protective.
If none of that works, then think about a more structured solution: secure the cables with plastic cable trays that close (way better than tape), run everything behind furniture or over shelves out of reach, or use those transparent silicone cable sleeves that exist for this. And unplug appliances when you're not using them - a cocky cat doesn't care whether the charger is plugged in or not. But honestly, boredom is the real culprit here, so invest in keeping him entertained and half the problems disappear on their own.