No one is scared of Reaves...
Here is a lovely play where both him and Edmundson go for a hit, are overly aggressive and end up costing us a goal within 3 mins of the first game after controlling play the entire time.
Yep. There are 3 Reaves experiences.
The first one is 95% of Reaves, and it's him trying to play hockey. He is garbage at this, and it hurts the team.
The second one is 4% of Reaves, and it's him attempting Reaves things and failing like the clip above. These hurt the team; sometimes quite massively and directly, like allowing an odd man rush for the 1st goal of a series.
The third one is 1% of Reaves, and it's him laying a big hit or fighting.
Now some people really really like seeing things go boom, and thus they try to pretend that the 3rd version of Reaves is not only beneficial to the team's chances of winning, but somehow makes up for the other 99% where Reaves is actively hurting the team.
Not only is that ridiculous, but it's also really questionable how much positive impact #3 actually even has.
Can it provide a marginal energy boost to the team (like many other things also can)? Yes, sometimes. But most of the time, it's going to have a negligible impact, and sometimes, it can wake up or boost the opposing team instead. It's not automatically a positive for your team, even if you are the one initiating the carnage. Exciting does not automatically mean beneficial.
The clip of Reaves you showed resulted in a pretty significant goal against. The clips that you're replying to, of Reaves making a big hit, don't seem to result in anything. The only team to score a goal in the period those hits happened is Boston. In game 3, we technically manage to score the next goal, but it's like 40 minutes later when any energy boost would be gone, and we lose that game anyway. Pastrnak getting wrecked in that clip didn't seem to intimidate or scare him away from scoring the series-winning goal against us.