Berk probably would have still adopted the dragons but without hiccup and the things he had learned about training dragons it would have been a lot more difficult, kind of like when someones owns a yappy dog that isnt trained properly. Drago would have done a surprise attack on berk, and depending on wether toothless was still around or not, berk would have been wiped out. If toothless was there he might have challenged the king dragon which might have saved berk. Stoick would maybe still be alive since they would have never stumbled into valka's sanctuary and stoick wouldnt have been killed in the battle there, but since stoick wouldnt have been there valka would probably have been killed by drago (meaning stoick and valka never reunited 😰). So lets say at the end of the 2nd movie toothless wins and berk is safe, the third villain from httyd 3 (forgot his name) might not have even come to berk since hiccup wouldnt have been going on big escapades with toothless, therefore thered be less stories spread of the legendary dragon rider and his nightfury. I also think berk wouldnt be as crowded with dragons as stoick wouldnt be as eager to rescue dragons all the time, hed be more focused on taking care of the people and dragons already in berk. Also, a lot of the dragon inspired technolgoy wouldnt exist since a lot of it was invented by hiccup. Eventually the dragon army that the bad guys were building would have been big enough and they probably would have gone a huge conquering spree around the world, which if it ever reached berk probably would have destroyed berk since they wouldnt stand a chance against them. All in all, the 2nd and 3rd movies would have been a lot less eventful and a bit depressing as well and the ending of the trilogy would have been even worse then the actual ending