Back when I played, nothing in Warframe was particularly hard. If anything it got easier because you get more and more overpowered stuff as you grinded over and over (which is really the only thing to do). The only time it got particularly challenging is when you do content that has scaled so far beyond normal play that you have to cheese so hard that you're effectively not playing the game as intended. I have fond memories of winning event after event with my clanmates but it's more the feeling of camaraderie rather than actually enjoying the gameplay.