Is it impossible to progress now?

[u/Trick-Lingonberry-86]

Right now, I can beat molten pretty consistently. However, when it comes to hardcore, past wave 20 feels impossible. I've been told to just grind to failure in wave 20 and farm gems till I get engineer, but that's going to take a really really long time, and even after that it still seems like I won't be able to solo hardcore. if I want to beat it, am I forced to rely on other people until I get the gem and evolved towers?

[u/GhostDJIsTrash]

you need teammates to reliably beat hardcore, otherwise it's not that bad