Pokemon Let’s Go does not have all Pokemon. There are seven generations of Pokemon with different species in each generation. Pokemon Let’s Go Pikachu and Let’s Go Eevee focus on the 151 species featured in Generation I. Pokemon Let’s Go is an enhanced version of the 1998 release of Pokemon Yellow that was released for the Nintendo Switch on November 16th, 2018.
Quick Answer: No
Pokemon Let’s Go features 151/807 total Pokemon that have been introduced across the course of all Pokemon games. In Pokemon Let’s Go players can catch, collect, and evolve Pokemon into different versions by purchasing evolution stones for Fire, Electric, Water, Leaf, and Ice type Pokemon. Alongside the original Generation I Pokemon, Pokemon Let’s Go features the Kanto Region which is the same setting that was used in the release of Pokemon Yellow. This region features multiple cities and places of interest to visit in collecting the 151 Pokemon in the game.
The game features the motion controls inspired by the mobile game, Pokemon Go. Though the two share some similarities, they are completely different things and Pokemon Go is not required to play Pokemon Let’s Go.