At the end of the day, LFG and LFG invalidated the entire purpose of guilds. this in return destroyed the community resulting in guilds of numbers, instead of guilds of people.
Guilds need people to exist, but people do not always need guilds. In classic, people needed guilds to progress (at least, in a general, and lead-progression sense). LFG and LFR have resulted in a devaluing of the social interaction which ultimately lead to lack of social interaction and the toxicity we have today.
to restore this we need only change the way they facilitate grouping. Its good they do that, but the que (ie the mythic grouping system is good, but the lfr aspects are not) aspect of it (perse) needs to be removed.
It would also be useful if the guilds themselves gain significantly higher benefits (more gold and the amount of guild quests a week) for doing guild activities. It would even be more excellent if players were part of a guild run on a raid or pvp group and obtained an extra piece of gear a week.
when it comes to pvp and pve mixing.
I understand that blizzard has issues with population and ques and they are doing things to help resolve those issues however, they are making the problem worse by blurring the lines.
further more toxicity can be easily removed from the community if there was more demand for people to play together and rewards from that. this seems to natively suggest that pvpers should be playing with pvpers and pvers with pvers and naturally the players will generally incline themselves to that methodology.
However, that being said there is this strong aversion in the community of having to do pve to be valid in pvp. This is a very serious aspect of it and one of the many strong and good reasons they need to become separate again.