first, do you know the Junk 1 shot combo for squishies? I not then look it up, You can use it to 1 shot a target in close to medium range and this will give you an edge in 1v1s agaisnt other dps and healers.
Second, I suggest on Gibraltar or other maps but i’ll use this gameplay as an example, try and situate yourself on the bridge infront of your initial spamming position, do this so you can have better sight line of the enemy so you can shoot at them, throw in a trap and you are basically on top of the enemy team. If they do take notice and shoot at you, you can quickly retreat to your old location and spam at them when they get around the corner.
Your job as junk is partly sheild break so if there are sheilds, shoot at them instead of trying to land long range nade shots on the enemy which is considerably harder. If they shield breaks then your team is more advantagous.
Agasint the enemy junkrat rip tire, you can really easily break the tire if you are able to land a concusion mine, try and predict where it will come from and place a mine there, if not then try and throw another mine at it to break it, attempt this more especially if you see the tire coming to nulify the ult.
If there’s a sheild tank on ur team, use the sheild as cover and never walk pass your frontline into the enemy, you can flank and it is very effective in low rank to flank w junk. Never walk straight into the enemy team, you will die and feed. Spam the frontline, flank, or attack from a highground position, always stay on the high ground because this is when you are least vulnurable and place a trap of the route the enemy can take to reach you.
I’ve notice that you love jumping from the high ground into the backline, DON’T do this, better players will kill you immediately and I suggest you stay on the high ground and pressure the backline at a safe distance, If you can perfect the 1 shot combo then getting a kill this way is far easier and if you decide to jump from the highground into the back line, make sure you have both ur mines and that you are confident you can 1 shot combo a squishy. If you failed to do so, use the other mine to get out just like you did in the clip and that is good, but make sure if you do drop down, secure an elim.
( I will edit this comment further so when I have more to say )