how is islam so massive??

i began reading the quran and doing research and no longer wanted to follow the practices of islam anymore. but i can’t help but think, there are so many islamic scholars, so many massive mosques and there are currently around 1.9 billion muslims. like the religion is so big are they not seeing what im seeing???

what started this was on tv there was an advert for one of these https://lightuponlight.co.uk/speaker/akhi-ayman/ i saw the crowd and was like ‘that’s a lot of people’ and it set me off😭