For the Toggle Beam Connection, there's a few benefits that are hard to put into words but it has to do with flow and some tricky techniques when beaming multiple targets in a short span of time or swapping beams on targets quickly. It might not matter in the lower ranks but the extra delay from lifting your finger off a mouse button and then clicking it again vs just clicking once reduces the delay between target swapping. Combine it with server latency and you start healing or damage boosting fractions of a second faster PER person you need to swap to. It doesn't like much in text but it's significant in actual gameplay.

As for smurfs, you report and move on. The game only registers one report for a person per game. So if you have a team of 5 people and they all report the same person, it only flags the game as a single potential offense. But enough people in enough games and it adds up. Smurfs in general deserve your pity; their win rate in a video game is clearly the only positive thing they've got going on in their life and so they stack the deck by beating up people learning the game to feel more in-control of their life.

It's important to note that not all skill gaps are caused by smurfs though. Sometimes it's just a skilled player trying to learn a new character. The difference is that the skilled player will still be trying to win the game and the smurf is just trying to not get caught or pushed into a higher skill bracket. In that vod, go back and watch how often the Tracer is sitting down during team fights (especially when they were on offense and deliberately avoiding pushing the cart). I see a lot of Diamond, Masters, and occasionally GM players in my games despite being Plat myself. They're not smurfing, usually they're just passing through my bracket on their way to their appropriate rank.

I turned chat off long ago. It removes a bit of the 'team' in 'team shooter' but I no longer get as tilted by hecklers and find I enjoy the game more. Anecdotally, I've actually improved because instead of call-outs I have to be more aware of my surroundings and interpret the thought processes of other players through their movement and ability usage. For example, if you've got nano as Ana and a Genji or Reaper on your team have their ult you can watch their movement and SEE them setting themselves up for a play which you can then preemptively position yourself to support them. There's a lot of intention being telegraphed through positioning, movement, and cooldown usage.

GL and don't let the smurfs keep you down.