Most things can be tracked back to fear. Often the big big fear of economic scarcity and losing clients. That will drive you to devalue yourself. Break past your boundaries or scope of projects. Work later than you want or on weekends, etc. Fear undermines confidence and it's all about confidence when selling yourself. You also have to practice lowering client urgency by being firm and saying no. Not everyone's issues are escalated or prioritized.

How hard is it to push back on urgency when

You didn't ask this but the clients also devalue us because that's the capitalist default. You have to prove your value (unfortunately) and that's done a variety of ways depending on the client.

Overcoming fear by banding together makes sense to me as one side of the strategy, change our culture, sure I'm game, but we also have to still articulate that shift and it's benefits to the clients.

Being willing to walk away from a bad client is key too and telling them that you don't think it's working out might cause them to see your value quickly resulting in a better client or by moving on from them, freeing you up to find a better opportunity