Title says it all.
A small example would be: You go 76 in a game. You pull 28-2 in two rounds. 15k+ in dmg. And you do this sort of thing routinely.
XX in elims, < 3 deaths a game. And high teens in whatever stat you need to have a high number in.
Does that matter at all?
no
if you win you win
if you lose you lose
Stats won’t change that
Within any isolated match, no it doesn’t matter a jot.
If you have gold healing as Roadhog then there’s probably someone doing something wrong
Stats do matter, however it matter when you use it to reflect on yourself. The issue is people’s interpretation of stats are as follows “I have 34 elims as Moira, therefore my DPS suck”. What they should be thinking is “I have 34 elims as Moira which is great, and I have gold heals, BUT my heals are at only 7k and it’s been through overtime. I should use my healing resource more for the team.” Stats do matter but it’s the lens that needs to be focused on
Beyond suggesting you are playing well or poorly?
Not really.
Probably the Roadhog who’s feeding tonnes of ult charge. So yeah.
Stats affect things like PBSR in plat and below. But they don’t really matter because winning or losing has a much, much larger impact. There’s no point putting up epic stats and losing if you could have done something slightly different to secure a win. E.g. if you stay in every fight after it’s already lost you will get more elims but hurt your team by staggering yourself.
Just do what it takes to win. The only stat that really matters is your win rate.
But stats will change how much sr you gain or lose. And they are boosting your mmr.
So they are important too.
I’ll give you an example:
In owl, when Vancvouver played against SF shock, Vancouver had double the damage and double the healing than Shock did.
Shock won.
Not after you reach diamond. Performance based sr is turned off at that point. Cuz at that point blizz considers you to be playing the game the way it’s meant to be played.
Example: You play tracer and you do 0 damage, but you disturb the backline and baits out ults and cds(trance and sleep darts etc.). Therefore the Genji can balde and get a 6k, while he’s matrixed by dva and outresourced by healers while their Winston is cornering enemies so he can blade them efficiently. It’s a team effort, so everyone gets equal sr credit. At that point the game is no longer about who is the better player, but who is the better teammate.
#stats don’t matter
I guess the answer would be both yes and no since your question is rather open for interpretation, like in what regard do you mean by “stats matters” and to whom?
But to put it this way, the only way most stats would be accurate would be in context to the game those stats were taken from. Like you can’t just take your season dmg per 10 min for example and think that anything lower than that by default would be bad because it comes down to time played, map, all the heroes in play and so on. Sometimes you can be very efficient even though not doing that much damage.
If you are trying to improve a character comparing some stats such as crit accuracy between seasons could be interesting.
All in all, it really depends in what way you look at it if it matters or not. Just remember, numbers alone don’t really paint the full picture.
Well comparison with owl league is pretty much useless because they are not playing the ladder comp 
About performance above 3000. Yes you dont have pbsr but your sr after 10 placement games is highly affected by your performance and by your mmr. So stats still matter for everyone above 3000. But game will use it only in placement.
Stats are clearly important, but everyone should play to win and farming ststs instead of playing as you should is definitely bad choice. Higher stats are very important in low ranks tho, they will help you climb a lot. But there is difference between playing to have good stats and playing good.
If your dmg is gold but elims are low its not that good because it indicates that you were feeding ebemy healers a lot for example. Its same for every stats. But if you have multiple stats in high numbers, it matters.
True, but they are playing the same game though. And you can learn a lot from them, even if you don’t play at their level.
I can’t dispute the rest of your reply 
True they are playing same game but as team. People in ladder are playing as individuals mostly.
Level of cooperation they have is non existent in solo q.
But they shouldn’t though. You gotta play around your teammates, or the game itself will punish you the way it’s built
I have had the most cooperative games even in gold lately (even if we didn’t win) people communicated, comboed ults, positioned as agreed on… I disagree, maybe I was just lucky though.
Depends in which rank you are playing. Its not very usefull to flex or help others below high plat and risk your life or performance. Its sad but mostly you will not get their help or good decisions back.
Just my experience from playing in EU.
Booooooo!
That’s all I’m gonna say XD
I don’t play for sr, i play to get better, sr is just a result, never a goal.
I came from Wow, if I didn’t want to play around other players I’d be playing a different game than this.
I didnt say i am not helping, just saying its not worth it in that sr range sadly.
I will give you example.
One game i risked my performace and life as mercy several times to do risky ressing of people who overextended like morons. And when i fell into to illios well and shouted for help in voice to fly to someone, what happened? They ignored me. I had this several times. People at this range care only about themselfs mostly.
Don’t even do that omg, thats not even good teamplay. And i’m basically a Mercy main.
You do them more favours by shouting to come back or not rezzing them. Your life is more important than theirs.
If a dps want to flank, either go with them to begin with so they don’t die, but never rezz out of position.
But your life is useless when that one death will result in lost team fight without me ressing the person. Deends on rank. Sometimes i see res as 50/50 chance. You would be suprised how many crazy resurections was able to pull off