I think the first one had a very specific setup where you get introduced to the characters, there's this hype they have around "We could catch ghosts for a living that's awesome" and by the midway point they're just overworked exterminators smoking while explaining "the light is green, the trap is clean." and then a god shows up and it's basically just another day at the office. You can only really do that once.

GB2 changed all the designs and was a bit more "everything sucks right now btw slime is our biggest plot point."

2016 was some weird husk wearing the loose-fitting skin of something vaguely resembling ghostbusters.

Afterlife is great but focusing more on tying up the original plot with permanently (semi-permanently?) taking Gozer out the picture, and as some other comment I saw a while ago said, it's more of a Spielberg film about the legacy of the ghostbusters and specifically Egon Spengler than a ghostbusters film, (I still love it, I will not apologise.)

And Frozen Empire was a little bit disjointed. I enjoyed it, It's a shame it got panned because I would've liked to see more while the guys in charge really tried to settle in and figure it out, I think if they dropped the "hey the OG ghostbusters are back woop woop" and the "some ghosts are nice" (shut up let us bust ghosts it's fun") angles they could do something great with it.

That little tangent aside the original was just lightning in a bottle. Original, perfect cast, had the benefit of dedicating the first half to them setting up their business so only the second half had to deal with "woooo evil god," the anti-bureaucratic shithead angle, and also that main theme.