If the dealer didn’t go last, everyone after the dealer would draw to try to beat him, even on a 19 vs. a 20. There’d be no actual game. And the dealer draws according to the rules of the table, regardless of what other players have done.
On a hard 14-16 with basic strategy, you’re hitting if the dealer is showing a 7+. Even with counting and deviations, you’re mostly hitting in those situations. Sure, any particular hit will be luck, but over time the mathematically valid approach will give the best chance for success.
The main advantages for the dealer are that his plays are given and that unless the house has done something really stupid, it probably has at least a .5% advantage over even a flawless basic strategy player. And that very few people can even play basic strategy flawlessly.
If you’re going to beat the dealer, you’re going to have to count, vary your bets, and do so without getting backed off. Whether some ploppy plays poorly or not won’t affect that in the long run and, either way, is about as likely to help you as hurt, you just notice the hurt more often.