Oofta
Legend
I had a player quit because I had a set of Wolves (which have Pack Tactics) focus on him. This char never went into even Death Saves over about 5 sessions...not once. But he felt my game was "too hard".
The only chars I have ever killed in the past 3 years were 3 out of 6 char party in one session because the players came up with an idiotic plan. (Split the party 3 ways going into what clearly was a trap).
But I am considered a "Killer DM" because of that, and often, chars do go into Death Saves.
So yes, more and more, I see players that are indeed "delicate flowers". A good player can whip up a char in about 10 minutes, sans backstory. But then they will invest 4 days into said backstory, and get very upset when the char is on the verge of death.
I'm pretty sure every PC in my game has been making death saves at one point or other. I'm sure it's been more than once for some, but it's not like I keep track.
On the other hand, back in 3.x days I was quite active in Living Greyhawk, the public game similar to AL. There was one guy that was only happy when they dominated combat (he played a wizard) and would pout if anyone dared attack their PC, much less knock them unconscious.
So it's nothing new. But once a PC is unconscious I don't generally continue to attack, although animals may start dragging them off. I try to spread the "love" and if one PC has gone down every other fight because they're a monk that doesn't have great tactics (purely hypothetical of course) I'll make an effort to focus on someone else.
There's a big difference between putting the fear, and very real possibility of death on the table and actually killing PCs. If PCs are just a pile of numbers and stats to you that can be replaced in 10 minutes, that's fine. It's what I do when I attempt to run an elf because they always die after a few sessions anyway (it's a curse).
Discuss lethality level during your session 0. I explain that death is never off the table completely and we go from there. Then if I get a player that pouts if I dare target them I may have to discuss expectations with them, but I don't see any reason to believe it's any sort of general trend.
People who can't stand to have their PCs attacked is nothing new.