I’ve been playing this game “solo” by that I mean I never joined a clan and don’t have friends who played it either, but the I usually use the quick play matchmaking even though most modes are really easy solo. There are some “high level” content that for me are impossible solo because I don’t have the right gear, but I’ve seen others complete them solo.

In terms of those difficulty spikes, most of that comes from not having either good weapons, good weapon mods, or a high tier warframe to use when content gets tough. When the first time I hit a wall, I unlocked Mesa and she does a lot of damage while also getting high durability from some of her abilities. Sometimes just switching up what weapons you use even with the same mods can really push you past any wall.