Munitions chain gun

And then they released celestial..

Well, Unstoppable can be clipped and needs to be fixed too.

Jackhammer? They've reduced its range from 15 to 7 but remains the same damage.

I just hate that that relatively small rifle is more powerful than a chainsaw grip gatling gun personally

Fixes to Earth were made already considering what you've mentioned.
Unstoppable can be used for clipping but it comes at the risk of melee range. Unlike plenty other Supercharge generators, it must be used in melee range for it to work and get damage/SC generation.
As for Jackhammer, the damage was toned down and then the range was reduced finally. Again there's a risk vs reward factor in play. Earth lacks at range whereas other powers may shine and vice versa.
One might say "There's a lot of content that players can easily melee"(and in those scenarios, yes, Earth may seem like cheese) however there are also plenty of situations where it is unwise to do so or even bother to try at all.