In my opinion, experiencing and consuming content with a group of friends elevates that content to unimaginable highs - whether that media content is movies or games, the experiences will always become unique in ways that solo experiences could never hope to achieve.
To give a handful of examples:
Movies, even when they are boring or poorly filmed, can become a social experience made more positive through laughter and the shared experience of “suffering” together. In the same way, being defeated in games can promote intimate camaraderie and teach valuable lessons. Being in a group makes those defeats more bearable - you fell together and you will rise together.
Furthermore, using communication and teamwork to overcome difficult obstacles feels better, in my opinion, than overcoming a similar challenge alone - being able to talk about shared victories is far more interesting than telling a story of your conquests to friends. Stories become more tangible and conversation is more engaging when the people involved possess those shared experiences - each person will remember their favourite parts and reminisce.
As someone who enjoys Dungeons & Dragons (tabletop) and adored games like Everquest, Divinity, and Baulder’s Gate, the party system has always been a crucial aspect of role-playing games.
Being able to clearly define your character in a role is interesting to me. Going outside of the standard playstyles like DPS, Tank, and Healer, it is always interesting to see characters that specialize in crowd-control, debuffs, and buffs.
Roles are important. I feel that the role a person plays often defines them - especially within a group.
My favourite role to play is support, whether that is providing party buffs or healing. I appreciate games like Everquest and Grim Dawn because I do not ever have to deal damage. In these games I can play almost entirely as a pacifist, I can specialize into the role that I want to play and play it the way I enjoy.
As a group, my friends and I (much like real life) are able to fill in the gaps that the others lack; we mesh together and function well together, collectively reducing our weaknesses and empowering each other to our fullest of potentials.
I don’t believe that there is a definition for “good” group. It could be argued that you could combine all of the most efficient “meta” builds in a group and say that it is “good” because it can clear content at the fastest rate… however, I believe that composition fails to embrace the true spirit of a party - where unique and impactful roles are clearly defined and benefit from being used together.
Path of Exile is an example of a game that used to offer unique party composition, where each of my friends were able to take on their preferred roles and I was able to play as an Auramancer with no damage abilities or attacks. However, after years of bad design philosophy (engineering the game strictly for the solo experience), I have abandoned Path of Exile with no interest in returning.
It is my hopes that Last Epoch will be a game worth investing in with friends. I am not interested in playing this game solo, there are far better solo ARPGs on the market.
Edit:
Reading through this thread and comparing similar arguments to other threads regarding trading being a negative, I just want to say, trading will always be a positive in my mind. I love stumbling across a piece of gear and being excited - not because it is good for my build, but because it would work really well for one of my friends (or perhaps a stranger that I could trade it to).
I hope that multiplayer trading can be properly and safely introduced into the game in ways that it cannot be exploited but still allow for free trade between friends.
GL HF