The swivel doesn 't make the action better, the snap does, lots of high quality hard swimbaits do come with a snap, actually they need it to make the bait wobble more freely, the same can be applied to cranks, there are baits that have a better action with a snap ( like the Rapala Original Minnow ).
Checking your line condition frequently looking for signs of wear is something you have to do, doesn 't matter if you tie direct or use a snap, changing baits quickly is no excuse for being lazy.
I 've fished for more than 30 years, the only time I use a snap/swivel combo is when I fish with in-line spinners because those no matter how much the manufacturer claims they still twist the line.
Also, if you are going to use snaps for crying out loud, DON 'T BUY "EL CHEAPO" !