I should've started by saying that I'm A+ and this was an A+ match since that matters a lot apparently
Don't assume players will be better because they're higher ranked, Nothing could be further from the truth. People like to think that is how it should be, and that is how it would be if the splatoon ranking system was actually good. But it's not, it's more for fun than anything. Not to say it's easy to get into the As, just to say it's not really an indicator of skill.
I main tentatek and I like to watch the flanks and ambush people. Tentatek is a great gun, but expecting people to go crazy with 1v1 brunt attacks and smash everyone with it and carry is a misconception. You'll still get rekt doing that. You're just one inkling. You can do a lot of work, but you aren't going to win against 4 other inklings without at least minor amounts of help.
Tentatek isn't the best brunt force gun. other guns can pressure better than it and outrange it in a straight up fight, which will be enough to conquer them if maintained well in many situations. it can still pressure, but it will get out pressured by other guns. Tentatek is great at exploiting opportunities to wreck people, and has the inkzooka to use if they can't find a good opportunity to get an up on the opponent's firing line, and sticky bombs are a nice boon to a lot of strategies.
This is what I dislike about people below A+. Always complaining about their teammates. Look, don't be salty. Use your entire team dying to your advantage by simply killing the whole other team by yourself. It's not hard, man. Just because Splatoon is a team based game, doesn't mean you need a team to win.
Your example is still playing with a team. Try doing all of that without a team. Unless they're all braindead retarded you're not going to get the succesful ambushes you apparently do, and you certainly won't win in a cold 1v4 from the start unless, again, they're braindead retarded.
A cold flank attack where they aren't distracted is a lot more likely to go wrong than one where you have bullet sponge brainless inklings who couldn't fight off another inkling to save Old Yeller from dying distracting them. The latter case is not playing with no team, it's playing with a bad team. there's a huge difference.
I agree people shouldn't complain about their team when they lose, as that doesn't help them improve. but saying you can win with no team is wrong. Some people on both sides of the coin undervalue what their teammates have done for them, especially if those teammates score badly. People blaming their team sees it and says "oh well I did better, so it's their fault and none of the blame could fall on me" people on the other side say "see? I did that all myself and my teammate did nothing". Even if he goes 0:6 he still did something that helped you, even if that's only acting as a target. When those numbers are all you have to go on, it makes it very easy to fall into that line of thought, since it's not like you have footage of everything everyone did. But it's not the same as playing with no team by a longshot.