Re: SBMM makes it impossible to play with friends.
@DangleKing666SBMM really does make it more necessary to play with people of similar skill level, you're absolutely right! It sucks for them, playing against the players that your SBMM pulls in, but on the other side of the same coin, it would suck for lower-skilled enemies that you trounce, if SBMM pulled more people around your friend's levels. I am lucky enough to not have to deal with this on Apex, as me and my two buddies are very close in skill level. I do, however, deal with this issue on Halo. Me and one of my buddies have been playing Halo since CE (20+ years), and one of our other buddies is very new to Halo in general. We literally can not play ranked when he is on, because he is just not up to par, and that is in no way an insult to him! He just doesn't have the experience that we have, and cant hang with us in competitive modes.
From personal experience, I found it worked best to just be honest with him, and let him know that it's nothing personal. He didn't take any issue with it, and we just stick to either other playlists on Halo, or we play one of the multiple other games that we all play together. You sound like you have a similar group of gaming friends as me, and have been gaming with them for numerous years, so honesty may be the best policy here. Considering how long you've been playing together, a simple conversation could solve everything.
Best of luck to you!! I know how great it is to have a group of close friends to game with, so hopefully it all works out for the best!
Edit: For giving advice about gameplay, just a bit of advice from my own experiences with it. I have the same issue with my buddies from time to time. I have noticed though, that it really helps when we offer advice when we are not currently in a match. Tensions/adrenaline run high in the heat of combat, so even a simple suggestion or piece of advice, can come across as insulting/degrading to their skill/ego/pride. I have much better luck when I wait until the lobby, once we are more relaxed, and then it is much easier to discuss what happened, and what we could/should have done different.