Hiya!
Sorry for not playing the game the right way.
It's ok, nobody's perfect.
It has a massive influence because the game is designed around combat and the design of the combat system promotes damage as the most effective means of succeeding in an encounter. Furthermore, there is a significant difference in power between sub-classes. This becomes exceedingly noticeable right at the very beginning of a character's progression and only ever gets worse throughout its career. Criticising people for wanting to lift a certain concept up to the levels of these premium builds really isn't very helpful or constructive, especially when all they want is for the playing field to be equal.
(1) The game is NOT designed around combat. It's designed around Combat, Exploration, and Role-Playing...with a glue of "use your imagination and make




up by playing 'lets pretend'".
(2) Your points about "significant difference in power" between subclasses and leveling seems to be only correct/applicable in the context of Combat. Out of that, which is,
by design, about 66% of the game...the 'combat discrepancies' are moot. A heavily armed and armored fighter sucks balls when he has to run from the law, climb the city wall, and swim across the river to safety where the horses are waiting. You know, all that other stuff that goes on between combat encounters.
(3) Criticizing people for wanting to play a combat focused game is, well, criticizing. But with 5e, I see the same stumbling blocks of virtually all the "combat optimizers" out there; 5e isn't 3.x/PF/4e. Trying to come into 5e with the assumption that all classes are balanced (or even
should be balanced) equally with regard to Combat is basically starting with the wrong question. With the HUGE step towards DM adjudication and player<-->DM cooperation, simply having some particular bonus, feat, or ability on your sheet does NOT mean it will be used that way all the time. In fact, I'd say that most 5e DM's more often than not will simply "modify" some particular feat/ability/spell if the situation deems it makes sense. For example, a player asking if he can pick out the best weighted longsword may point to his characters Weapon Master Feat for why his sorcerer should have a chance to do that. Is that by the book? Nope. Does it make cool, narrative sense from a character perspective? Absolutely.
Anyway, my point was that "Combat equality being required" is, thankfully, a thing of the past...at least IMHO. Obviously you and those other folks who focus on combat as the 'core' of their campaign think differently; not a bad thing, but, as I said, there are better games to give/handle that style of game more so than 5e's loosey-goosey "rulings not rules" and "Three Pillars of Play" design.
^_^
Paul L. Ming