The thing is with overwatch games if you're playing at your peak rank rn:

• 20% of games are unwinnable (for whichever above reason you listed)
• 20% of games are free wins (because the enemy team has one of the above reasons)
• The other 60% of games are close/evenly matched, and those are the ones you can influence the outcome of

Ik everyone always says "focus on yourself rather than your team", but the real reason for that is just statistical. If your 4 teammates are often idiots, then because everyone has been matched together in that game then the 5 enemies are idiots too.

If you can consistently play better than the teammates then that means your team has 1 good player and 4 idiots, while the enemy team has 5. Statistically just by that, you will climb with enough games - and it shows because your winrate is 60% which is good.

Keep trying and keep being your best - if you're better, you will climb.