So I'm relatively new to the scene and only played with 1 DM. This last campaign we did Out of the Abyss with a party of 6. Several of the characters got pets or familiars at a certain level, at which point the DM restricted any additional pets or summons. I was bummed as I was a Druid and this prevented me from using a good chunk of fun spells (summon fey, conjure creatures, etc).

I mean, I get it, adding 8 creatures to a combat round will make it slower than it already is with 6 players and pets, but what are some options to help with this other than simply banning mechanics? The campaign is over now so I'm mainly interested in lessons learned for the next one.