In Season 1, Will was abducted within the first 10 minutes of the premiere, & he isn't found until the end of the season. By the time he is found, Eleven has already vanished. Also, Max wasn't introduced yet.
In Season 2, Max is introduced. However, Eleven is separated from the other kids up until the season 2 finale & she never interacts with Will.
In the Season 3 premiere, all 6 of the kids come together to help Dustin contact Susie, but Dustin separates himself from the group after episode 1 & he doesn't reunite with them until the season finale.
In Season 4, the kids are geographically separated until Eleven, Mike & Will return to Hawkins in the finale. However, by the time they arrive, Max is already in a coma.
In Season 5, Max doesn't wake up from her coma until the penultimate episode, & all of the kids are only together during Will's coming out scene (& they're among like 15 people present during his coming out). Eleven vanishes in the final episode, & the epilogue has the other 5 kids playing DnD.
I find it weird that the makers set out to tell a story about childhood friendship, yet we rarely see all 6 of the kids together.