No one would be trying to finish off enemies because raise dead exists. Once a combat begins, everyone has to fight to win, not waste time.
Raise dead and spells like it are after combat, healing word, cure wounds and the 'mass' versions of those spells are much more common and happen in combat.
So drop any obvious healers first if you can, and kill anyone you don't want to get back up before moving on to the next target.
PC fighting enemy with multi-attack, first attack drops him to 0 h.p, sure the enemy can move over and make an attack without advantage and maybe hurt another, or he could attack with advantage and keep the guy he just dropped from getting back up again.
Yeah it sucks, but a good number of monsters and npc's will use that extra attack to complete the job and get that critical hit in for 2 failed death saves, it still gives the PC a chance to live just not a very good one.
Just saying no one is thinking about raise dead during combat that is for after the fight, understanding magic healing effects are used during combat is something the inhabitants of a D&D world should expect and take into account with their tactics.