Since my last reply here caused a controversy, i’ll try to explain in a nicer way, why i said these things in response to @ChamomileHasGames as i said. And perhaps, to clear some bad blood. 
@ChamomileHasGames, you said that the description of Easy mode didn’t meet your expectations and the game didn’t turn out “a walk in the park” (to say so). You died more than you expected to die and you also struggled when facing Rivals. Thus, game disappointed you when it said in the Adventure mode description that the gameplay would be more story-oriented than combat-oriented.
Here, i agree with you. The difficulty level descriptions could be better.
You also point out that rockets (i guess you mean HE rockets, fired with m/49?), doesn’t live up to their name and you need to use several to take down bigger machines.
Thing with HE rockets is, that they are High Explosive and are intended to use against groups of smaller machines. You can take down bigger machines with HE rockets but since HE rockets aren’t Armor Piercing, you need to fire quite a lot of them, to eventually bring bigger machines down.
There are requests to bring AT version of the rockets to the game, so that m/49 would be more effective against bigger machines but we’ll have to wait and see if devs add those in the game.
You also say how the game should be on Adventure difficulty and especially for solo players. Here, you present your subjective understanding on how games should be when it comes to Easy difficulty.
Thing is, i don’t know from where you come from and what kind of experience you’ve had with other games. For all i know, you probably have played easy games in the past (e.g minecraft) and once you arrived here, the Easy difficulty in GZ is too hard for you, since you’re used to easy games.
That, in itself, isn’t a bad thing since different people prefer different difficulty level games. There are people out there that prefer easy and casual games (from time to time, i also play such simple games), then, there are people out there that want the toughest challenge game can give to them (e.g any regular Dark Souls player) and then there’s middle ground between the two extremes as well.
When i said that i play on Guerilla and prefer it even harder than it currently is - it wasn’t said with an intent to show you that i’m the greatest GZ player. No, not at all. Instead, i said it to show you from where i come from.
GZ is not an easy, casual game. GZ is currently somewhere in the middle. Though GZ used to be a difficult game, when it launched back in March '19. @OBiW4NSHiNOBi described it well how GZ used to be.
I stated to play GZ 1 week after it’s initial launch and things were very tough in the beginning, especially since i didn’t know nothing about machines or which tactics work the best. It took me about 117 gameplay hours, in my own slow pace, to finish the main vanilla missions. I was learning with every step and i never gave up. As the saying goes: “When things get tough - the though get going.”.
I also suggest that you never give up. 
If direct attack doesn’t work, try luring one or two machines away from the bigger group and take them out one by one. Or perhaps snipe the machines from afar. There are many different ways how to take machines on.
As far as FNIX Rising content goes, and as said before, it is late-game content. Here, i suggest that you leave it be and go elsewhere. Once you’ve gained more experience and better gear, come back to it since machines aren’t going anywhere. 
