It's very important. You can play a bit of mind games with some techs. Say for example, someone decides they want to forward smash you, but you can wavedash out of that and hit them right back. Dashdancing is also a move I personally use, and most other people who play competitively do that as well. Dashdancing is also mindgames because it gives more control to turning out of an opponent's attack and hitting them right back (I could be wrong on that and there's definitely more reasons, but trust me when I say dashdancing is useful when used appropriately.) Point is, it's very important to do these techs. Tell me, have you seen any, ANY melee player that doesn't do a single tech (or much less than usual) and is beasting at tournaments?
I'm surrounded by noobs my friends and EVERYONE ELSE AROUND WHERE I LIVE who barely give a crap about techs in melee and think things like spamming Thunder with Pikachu or just trying to be a troll by doing this other stupid thing and they challenge me to a 3-stock or 5-stock match. I either lose 1 life out of carelessness, or I don't die at all. Trust me, practice your techs. Makes it all worth it. At least you have dedication in learning these techs, and that I applaud you for.