Whoa I'm hesitant to say NEVER.
If a player can choose a Character C that is exactly the same as Character B, and a whole bunch of other options, it will NEVER be the case that Character C will be worse than Character B, in their own judgement, unless they're just being irrational. Custom feat selection is a full substitute for choosing a Theme.
It is highly likely that there will be a Character C that is superior to Character B, simply because there are so many possible Character Cs.
Speed of generation. I'm en experienced player but I tend to go with suggested options and stuff because I'm also lazy.
So if they printed a pregen character for each class, would you go with that, even if it was woefully ineffective compared to what others in your group were playing?
See, I have players like you in my group. They don't like building characters much, so they switched over to Essentials characters when they came out. But I know they would not have done it if the Essentials characters weren't solid characters in their own right. If Essentials had simply been a bunch of pregen versions of the original classes, I seriously doubt they'd even consider them, because they'd almost certainly be far less effective than the characters they had before.
But in any event, if you don't
care about how effective your character is, only that there be a simple easy thing to pull from the book, then I'm not sure what there is for you to dislike about my suggestions. You'd still get a simple thing to pull from the book, you'd just end up with a character that's
better than it would be under the current design, and more likely to not be overshadowed by others who chose their feats by hand.
This is the part that I'm confused about. No matter what you want to call it, it's still a collection of powers that mix together to form a certain power level.
This isn't about calling things different things. This is about the specifics of how things are mixed together, and how the power levels result.
"choose a Theme that gives 5 specific feats" is almost guaranteed to be inferior in power level to "choose any 5 feats you want, including all the feats Themes give". The latter could reasonable be expected to compare equitably with "choose a Theme with its own unique features".
If a certain combination of feats is inevitably outpaced by an experienced min/maxer all the time, then it will be the same in this case as well.
It's a matter of degrees.
If a Theme is designed to be good in its own right, and cannot be literally duplicated by the custom feats options, then that puts a much higher bar for the optimizers to outpace it. Will the optimal feat combinations still be better? Probably, but not by nearly as much as if the Theme was just a collection of feats, that could be literally duplicated custom feats options.
Consider that an optimized 4E Slayer vs and optimized 4E PHB Fighter is quite likely to be about on par, even though the 4E Slayer is much simpler. It's almost inconceivable that WotC would publish a pre-gen Fighter that was on-par with an optimized Fighter.
I think the only way to solve this, based on what your saying is one or the other in total. You can't have feats in the game if you have ability collections, and you can't have ability collections if you have feats. (Provided you agree with your other statements.)
I don't think that's at all true.
Well designed Themes could certainly be competitive with custom feat selections. I only think Themes that are just pre-gen packages of those feats are a bad idea, and almost certainly won't be balanced with custom feat selections.
Just as class options with a lot of class features (4E Slayer) can be competitive with classes with a lot of customizable power choices (4E's original Fighter).
Would you say 4e ran into the problems you described with their power groupings?
4E deftly avoided the problem, with Essentials. I want 5E to take the same approach with Themes. Simpler should not be weaker, and Simple mechanics being a strict subset of Complex, customizable mechanics almost invariably leads to that.
Outside of Essentials, 4E didn't do many tradeoffs between mix-and-match-able options, and monolithic collections of abilities. I guess there's Paragon Multiclassing, but that just goes to show how mix-and-match options
can be inferior to the monolithic collections of abilities.