Lots of strong (one could even say extreme?) opinions in this thread, and gems of wisdom in most of them.

One facet that I didn't notice being mentioned was the notion of commitment to the group and/or ideals (or, if a business, contract). This was obliquely touched on in the "can the band get along without you" question, but did not seem to be explicitly listed. (or I missed seeing it in the various posts)

If you have made a specific commitment/promise/contract with this band, then that needs to be a factor in the discussion & decision. Not saying you must stick with your commitment come hell or high water - if the situation has changed significantly over time (as it appears from the description), then that promise may need to be re-thought. But it seems a bit narrow-sighted to simply say "leave whenever you want to".

If you have a personal commitment to an ideal, a Cause, and/or God, then consider if a) your continuing in this band can actually help fulfill that commitment rather than interfering with it and b) if you could continue that commitment without being in this particular band.

If there are contractual agreements, including gigs the band has committed to for the future or intellectual property rights (songs written or arranged or recorded), then the contract will need to be revised to adapt to your departure. That's the business/legal version of reconsidering your promise. If your departure would make it impossible for the band to fulfill it's future contracts, that does make it a bit more sticky and liability will need to be considered.

Sounds like in this particular situation, a departure is called for. A responsible person will make reasonable effort to not simply abandon promises or commitments. I assume you've made appropriate efforts in that wise.

Good luck with your future musical endeavors!

Val