Why in the episode mystery at the light house was the dragonite so huge and Bill said it the was only one of it's kinda if theres a lot of other ones (only they're like 7ft high?)

yeah what was up with that?

There have been several Pokémon that have been bigger than normal size. For example, Drew's Roselia is as big as a human child when it's normally only a foot tall.

The anime made that Dragonite so big and said there was only one to emphasise the fact that it would be a legendary if it wasn't an evovled form, or a pseudolegendary.

Because Pokémon was a good show back then. Now that it's solely meant for selling the games (not that it wasn't before, but it was just a little more independent and creative), and they have nothing new to come up with, awesome, mysterious Pokémon like Dragonite were made not uncommon monsters. Nowadays, any good trainer can have a Dragonite, whilst before that thing was amazing and a rare sight.

Pokémon lost its magic a long time ago. Good times.

Galar is 200% right. For example, now the anime is focusing on showing new Pokémon, or ones they haven't showed. Back in the beginning, Pokémon were getting caught left and right, and now, there was like 63 episodes since the capture of Buizel, to the capture of Swinub.