+/- is not a meaningless stat. It is a meaningless stat when you compare players on good to players on bad teams 1:1. But, +/- is a revealing statistic amongst their own teams players. Guindon, compared to his peers on his own team was CLEARLY the weakest 5 on 5 player. He was a -30. Goure was +7. 1st line centre vs 2nd line centre.
Beck was a +4 on the Ottawa team in 2021-22 that finished 3 games below .500 (-51 GF vs GA). His peers were well into the deep minuses. Guindon, on a similar team that was 1 game below .500 (-28 GF vs GA) finished at -30. There was a 37 goal differential between him and their 1st line centre.
So, yes, Plus/Minus does have a meaningful use when used properly. When you compare apples to apples, plus/minus can be a very revealing statistic. When there is a +37 goal gap between your 1st and 2nd line centre, I do feel it is realistic and relevant to point it out and use it as a viable metric to evaluate performance.