As a non-optimizer who can't stand playing with optimizers, I want to understand your point of view better.
I'll try answering all your questions in turn.
I'm curious what you mean by this. I've felt like this in a 4e campaign, and it was mostly a DM/player expectation mismatch. Are you just talking about the minutiae of each round of combat RAW?
What I'm talking about is the balance between the importance of dice rolls compared to the importance of tactics(choices in play) or building an effective character. Compared to all previous editions, 5E places more importance on the randomness of dice rolls and less on other considerations.
Are you saying you'd prefer greater specialization among PCs (like the 4e "roles"), a greater gap in effectiveness between players of different skill levels (like the 3e feat puzzles), or neither or both?
Not exactly that. More along the lines of I'd like my choices in character creation to have greater agency/impact on the game. I'll give two examples: 4E tactical play and 3E Rocket Tag
4E tactical play for me had a lot to do with picking powers, feats and abilities that gave you good options that had a big impact in play. There were very few "I win" buttons in 4E, so it was a mix of picking strong powers that accomplished more, teamwork, and timing. In addition, 4E tactics was generally about the big picture, not one action. It was more like building a house, where you and you allies combined actions over multiple rounds to accomplish things, while the environment changed around you. It really didn't matter if you miss or fail on a single action if you play smart long term, as monsters and PCs were both durable enough that a run of bad luck rarely was decisive. Another important aspect of 4E was that you didn't have to sacrifice your attack or offense in general to do interesting things. The Fighter could tank and hit like a truck at the same time. The Cleric could heal and buff and attack all at the same time.
3E Rocket Tag on the other hand was all about "I win" buttons. Things may have been out of balance, but you could certainly build your character so he had a dramatic impact on play. In 3E, you set up the "I win" button(both in character building and in play), and then you pressed it. If it failed, you repeat the process. A lot of the time, you could set yourself up so the dice had little impact on the outcome.
In 5E the dice are king. Combat goes faster than 4E, so a random swing of bad luck has a bigger impact, and it lacks 3E's "I win" buttons that bypass or minimize the impact of dice.
I assume you're talking about the dying rules. I agree that this is a problem for certain styles of play. House Rule: If you fail a death save, you die. It still takes 3 successes to stabilize. Also you have to roll a death save immediately when you hit 0 hp.
Not really, that isn't the point. My point is whether or not your choices matter. In 5E, the lack of lethality tends to mean that your choices or whether you succeed or not rarely matters in the long run. At worst, you're probably only going to eat dirt for a couple of rounds. 1E/2E was often(though not always) as random as 5E or more, but your choices mattered more because the consequences for failure were more dire.
All things are relative. Everything in 5e is very fragile compared to everything in 4e. I've seen """"tanks"""" be very durable in 5e (relative to other creatures in 5e), especially the Barbarian with healer support.
In 5E you're fragile, even in the best of circumstances. A short string of bad rolls will screw you over, multiple enemies focusing on you exclusively is going to take anyone down in short order. Above that, having significant defenses is a big investment and you have to sacrifice a lot to get them. Compare this to 1E/2E where a Fighter with a few levels and some decent magical gear was dramatically more survivable than the other PCs as well as 90% of the monsters you'd encounter, or the 4E Fighter whose base Defender chassis was enough to tank on its own, and you could customize yourself for damage, control, mobility or whatever because your defenses were already enough.
I'm not sure what you mean here. Defenders in 4e were definitely supposed to take hits so the rest of the team didn't have to; that was their core mechanic.
In 4E doing the Defender role wasn't a sacrifice. You could hit as hard as the Rogue or control the enemies as much as the Wizard. In 4E Defender was something you did in addition to kicking ass. In 5E, being a defender pretty much requires you sacrifice kicking ass.
Okay, I think that answers #2 above. So you'd prefer a system whereby players with superior rules knowledge are able to create significantly more effective characters than players without such knowledge, correct? May I ask why that appeals to you?
That tends to be the end result, but it isn't what's important. What's important is being awarded for smart and effective play, and having my choices have an impact on the game. The randomness of 5E detracts from that, and the game as a whole lacks options and choices that have significant impacts on the game compared to all of the earlier editions.