My experience of it so far (in 2 charities, one big national, one small) is that it is often a shambolic, badly organised mess. In the national charity there were a huge amount of 'managers' with permanent contracts while all the project workers who were actually working with vulnerable people had short term contracts that could go poof at short notice. Funding is obviously scrabbled around for desperately given that statutory services are barely funded. There is such a mish mash of people working there on separate projects that there's no sense of team work or support. In the last job I had o was working with extremely ill and vulnerable people with no real support and a manager who'd worked in housing all her career and thought mental illness was mostly made up and attention seeking.
I went into the third sector hoping I would be able to use hcp skills in a more flexible way but my experience of it has been eye opening. Also come across a fair amount of people just coasting until retirement. I know you get this anywhere (and in the NHS) and I have been hopelessly naive about working in the charity sector but I find it so depressing. AIBU to think this is third sector working or are there well organised charities out there who value and support staff. Just so down about it.