He was directly asked *BY YOU* to name a situation where a single d20 roll would determine whether or not someone would take 20d6 of damage. Don't be purposely obtuse.
Which still isn't relevant when the discussion was problems with the fighter's non combat capability. We already know the fighter is capable in combat. It seems disingenuous to mention a combat oriented situation in a discussion about non combat capability.
Besides, there are plenty of ways a single roll can lead to 20d6 damage in combat near a cliffs edge. A warlock eldritch blasting you off a cliff only needs to hit your AC. A spellcaster can thunderwave, grease, gust of wind, or use any number of spells that cause forced movement.
Saying a fighter with lucky is good because in a certain edge situation he has a decent chance to not fall off a cliff as long as the enemy is using an Athletics related method to push him off said cliff, really doesn't really seem all that relevant to me.
And again, why is no one in your party EVER willing to cast Bull's Strength on the Fighter? Is it because of your constant complaining?
Why cast it on the fighter? It would be a waste. The bard is the one who can shove people as a bonus action without giving up an attack to do so. the fighter's attacks are better put to use attacking the creatures the bard has knocked prone utilizing Great Weapon Master. It is merely an added bonus that Bull's Strength benefits the bard outside of combat and has an hour long duration. Also, the bard has a higher base Athletics check anyway, making the bard the more obvious choice for the buff.
If you never get pulled into a tactically disadvantageous position, you have a terrible DM. What if a cartload of orphans are teetering over the edge of said cliff and they're surrounded by your hated enemies? What if the precious MacGuffin is dangling over the edge, and the enemies are closing in? What if you need to get from point A to point B and don't have time to check for a cliffside ambush?
Heroes don't always get to choose where and when they fight.
A five-foot wide path winds along the cliff's edge...
Sure sometimes bad situations happen. I get that. But arguing that a fighter who spent his bonus feat feat on lucky is better off than others in such situations is ludicrous. I would much rather be a warlock with at-will levitation, at-will knockback on a ranged attack, darkness, and teleportation. Or a druid who can turn into an air elemental. Or a bard who has a massive bonus to athletics checks and bulls strength, and the ability to shove as a bonus action. Or a raging barbarian with advantage on all STR rolls while raging. Or a wizard who can use gust of wind to knock all enemies off the cliff at once. Etc.
In a tactically disadvantageous position, many PCs have abilities that can shape the battlefield around them. The fighter is still mostly stuck with dealing and taking damage.
It's pretty hard to cast a spell with verbal and somatic components when a gargoyle has one hand over your mouth and the other around both arms, you low-strength warlock or wizard. Looks like you need a FIGHTER to PUSH the grappler off the caster to inflict that forced movement.
Too bad for you grappling doesn't work like that in 5e. A caster can cast spells while grappled just fine. Maybe a better understanding of the rules would help you grasp the situation better.
So is a net. Throw a net, Fighter.
Nets are good, but their range is short and their accuracy is low (disadvantage beyond 5 ft and a low DEX bonus means it is hard to hit things as a strength based fighter). Besides, if the flying enemy is more than 15 feet away, you can't even hit it with a net. It is generally better to to let others throw nets or otherwise incapacitate flying enemies then you can pound on them when they are grounded.
You don't seem to actually enjoy playing a mundane character. You're hella jealous of the casters. And your mind seems to only work in a way that responds to challenges by thinking of all the spells for that situation instead of how your character who has to operate within the bounds of reality can still overcome the challenges.
I love playing martial characters. They are my favorite types of characters to play. I really enjoyed my warblade in 3e, my fighter in 4e, my fighter in 13th Age, and my non-magical warriors in Savage Worlds. So clearly you don't know what you are talking about...
I only play mundane characters. I love showing up the casters. You just have to approach it from a position of "I can do whatever I want," instead of "the character I built from level one is optimized for DPR and not mechanically optimized to make me the best at everything, boo-boo-bee-boo."
Lol...you really need reading comprehension. When did I ever ask to be best at everything. Hell,w hen did I ever even ask to be best at anything? I never once asked for parity with the spellcasting classes. That is simply an impossible goal. There is no way a martial character will ever be able to achieve the variety of effects or utility provided by spells.
All I want is a martial warrior who has a variety of interesting options in combat and enough utility outside of combat to actually feel like they contributed significantly to overcoming some non-combat challenge every now and again.