I'm not the only one with this problem all of my 90 habitats are full except some that I keep for the monster I send for extract, and I have 15 unique monsters in storage waiting from a while for new island and more habitats.... Why not instead a new island having like it is with booster and temple? A kind of thing like that giving the possibility to upgrade habitats for a higher number of place, of course upgrading the gold maximum.... Or just do it like usually, put a new island, anyway we need a solution please, all my monsters are feeded to the maximum and the game become boring in this way

No your not and your not the first with this kind of solution. SP is working on a solution and we all hope it comes quick you can read for yourself in Updates, hot topics Q&A (July2017): Upcoming Feature

@Stephane-L Agreed we desperately need a solution ASAP. My understanding of the problem is that many phones cannot reliably handle many more monsters at a time. Upgrading habitats further doesn't address that. They need something to store away monsters that you can pull back out if needed.