I will explain but you need to read the sidebar. Judging by the shitty advice /u/seedang has offered, he needs to read the sidebar too.

Monk mode is a period of time dedicated solely to self-betterment and introspection. It's a time of zero distraction where all that matters is self-realization: knowing what you want in life and laying the foundations for that to happen. Discounting monk mode is like discounting the need to learn how to walk before you can run.

Yes there are people who use monk mode as an excuse to avoid their problems but those people aren't really in monk mode. By it's very definition monk mode is a time of introspection. Introspection entails looking within yourself to identify your own shortcomings and face your own problems. Avoidance of the above is not monk mode, no matter what people say.

Lifting is important and it goes without saying why though I'll tell you anyway. We lift not for the purpose of being attractive to women, but to instill a sense of our attraction with ourselves (read here as narcissism). If you put sweat and effort into sculpting your own body, you can bet your perception of yourself will be that much higher than if you didn't.

In the same vein, monk mode is a means to sculpt the masculine mind within you. It's an exercise to accept that you have made mistakes in the past, that you can identify those mistakes, and know what to do to correct and avoid them going forward. Both lifting and monk mode are important but the importance of the latter should not be underestimated. As a man, the fastest way to better yourself is to improve yourself physically and mentally. In fact the two often go hand in hand. You need to know where your problems are before you can address them.

In the case of OP and seedang's advice telling a beta man who's stuck in an shitty LTR with delusions of holding frame to end the relationship and go out lift and fuck bitches is not only bad advice - it's stupid. How is he supposed to go out and fuck bitches when he doesn't realize that it's his own neediness which has put him in the shitty LTR to begin with? How is he supposed to get over his own neediness if he doesn't see the reason to put in time to invest in himself to identify what he did wrong without the distraction that women present?

These things don't just happen by accident. You don't magically end up in the gym one day and decide to lift the world. You don't magically decide to go out and fuck bitches. The time to reflect is not only important, it's necessary. That's why monk mode is recommended so much. Because without the mental, you will never attain the physical.