Manbearcat
Legend
I've seen that claim many times as well. It just doesn't hold up in play when you have a group of players that are (a) familiar with, and good at, synergizing, (b) know the "pitfalls" of what they are doing and how to compensate, (c) spends their various resources wisely, and (d) manages their workday such that they don't overextend themselves.
Well then. Since your post was just the rhetorical flourish of juxtaposing my a-d header with your own mirrored copy and didn't address the meat of my post (which would have been the broken out 1-11 below), I'll assume you just aren't interested in having the conversation (about your take that Warlords are overpowered when coupled with Strikers in 4e, hence your read that it logically follows that they would be overpowered in 5e). Or perhaps you don't consider it thread-relevant. If it is the latter and you'd like to have the conversation, then by all means make a separate post about it (perhaps in the 4e forums if you feel it is more relevant there).
(1) Average workday of 3 difficult non-combat challenges (whereby PCs are taxed Surges on micro-failures and macro-failure is punitive with respect to the stakes and story trajectory), and two combats of level + 2-4/level 5-8 (depending on tier).
(2) Little to no melee control can be devastating.
(3) What is that Striker going to do if I spend a fair portion of my encounter budget on Traps/Hazards that serve as blocking terrain/control/damage and can't be ablated via HPs?
(4) How much damage potential value is lost when you're trying to manage an encounter with level + 2 Artillery Minions that are protected by terrain?
(5) What about when you're being slid next to an abundance of Challenging Terrain that immobilizes or puts 5/10/15 damage on you...
(6) ...by a Solo Controller who crushes you with status effects and is protected by...
(7) ...Swarm guards that take the blow for the the Solo Controller and eat your super duper Striker damage (1/2 single target damage against them) as an Immediate Action (thus mitigating it dramatically)...
(8) ...and chew through your (low) HPs with their Aura auto-damage (or the Aura halves your, already meager, Surge value)?
(9) What about when the goal of the encounter isn't about HP ablation (which is the only thing you're good at)?
(10) What if it is about saving a little (Minion) girl when her skiff is attacked by a giant Tentacle Monster who has a dozen or more Tentacle Minions and likes to throw you in the water and drown you (which would be about melee control/action denial/multi-target control and dealing with punitive terrain/control)?
(11) What if it is about defending against wave after wave after wave of slimes and oozes that are seeping out of the ceilings/walls/floor until your ally (NPC or PC) can successfully exorcise Juiblex from a possessed fallen Paladin in a "haunted" throne room (via a difficult Complexity 3 SC)? This of course is about possessing (i) necessary control, (ii) "staying power" (which includes handling spike damage...which revolves around melee control, damage mitigation, requisite defenses, requisite HPs), (iii) and the breadth of relevant skills (Arcana, Diplomacy, Endurance, Heal, Insight, Intimidate, History, Religion) to successfully execute the difficult C3 SC.