@Meanlucario
That makes sense because there is one guy that won’t let you through the gate until you get Fresh Water. Which you can buy from Vending machines in Celadon City.
Of course, in FRLG you instead need to obtain Tea from the old woman at the Celadon Mansion to give to one of the guards (the vending machine drinks won’t work). No idea what you had to do in Let’s Go though…
Also, I assume that since the arcade games at the Rocket Game Corner aren’t playable in Let’s Go, you can find Porygon in the wild like how all the Safari Zone-exclusive Pokemon were relocated to different areas?
@Jarkes
I think a guy near there gives you one. Also, you can pay a woman in LGPE to set the nature of all mons you encounter for the day, which will be useful.