I'm a regular poster but have namechanged as this will out me big time in RL.
I worked in the zoo world for a decade and many of my friends still do.
Most of us would agree that there are good zoos and bad zoos, same with everything. The answer is not to boycott all zoos, but to put pressure on those we are not happy with to get up to a decent standard.
There are animals I am uncomfortable with in captivity - some have no need to be there and we need to question why they are there. Others have little to no future in the wild and the captive population is a way of trying to ensure the species doesn't become extinct. Better extinct than in cages? That's a whole different debate but for my part I think not - once an animal is gone it's gone for good. If we hold a population in zoos there is the chance of one day getting them back where they belong.
Close zoos and give the money to conservation? What money? Without the zoo, it wouldn't be generated. Although some organisations (eg WWF) manage without zoos, they also get money from people who are interested in conservation. Zoos attract funds from people who just want to see animals and who wouldn't donate at all if they didn't get a fun day out from it. So conservation would lose out. And that's why you have things like meerkats. On the whole, animals like this do well in captivity, a huge amount of time is put into ensuring that they are kept busy and active, and they please the paying punters. So not every species is kept because it has a conservation purpose.
To give some concrete examples, Jersey Zoo (Durrell Wildlife) is involved in 45 conservation projects in 14 countries, including Madagascar, St Lucia, Mauritius and India. With many of these, the staff are Durrell staff just as much as those in Jersey, but they happen to be, eg in Madagascar, Malagasy people working in their own country rather than Jersey. They are involved in projects ranging from helping to build schools (on the basis that most villages are poorly equipped and when people are living a meagre existance, conservation is a luxury, therefore help the people and then they in turn will be more willing to help you help the animals), community education programmes, rebuilding habitat and captive breeding of animals in their own country ready for release.
All this is supported by having Madagascan animals in Jersey, so you can say to people - 'Look, this is the animal we are trying to save, this is what is happening in the wild, but we need the money'. People stump up far more readily if they can see it for themselves. Not everyone, tis true, but most.
The other thing that happens is that work with animals in captivity can inform work in the wild. Monserrat orioles for example, really rare birds, were brought into captivity for the first time a few years ago. The captive birds were then used to try out harnesses for fitting radio transmitters, before the designs were taken out to the wild. Information on how the animals breed can be handed back to field workers to ensure nesting sites are better monitored and protected. Staff with skills at handling animals in captivity can be sent to the wild to help field staff (who may know how to track an animal but no idea how to handle it quickly and effectively with minimal stress) - this happened in Madagascar with the Giant Jumping rat when genetic studies were needed in order to figure out what was happening with the very small wild population. Keeping staff went out, because they know how best to catch and hold the animals, massively reducing stress for them.
I also know bird staff who've gone out to field projects to help hand rear chicks - eggs were taken from the wild because of massive predation by cats (not a nautral predator), the chicks hand reared, and then released, often in new locations to try and establish new populations where they have previously existed but now become extinct. You need someone who regularly handles very fragile baby birds, who has managed a range of them (it's not a one size fits all situation so knowing how a range of baby birds can be hand reared is important - zoo keepers have this as it is the nature of their job, field staff rarely do).
The reality in the wild for some animals is that even protected reserves aren't safe. I'm thinking of orangutans, for example, where in Borneo, protected forests are thought to have decreased by around 56% between 1985 and 2001. Illegal logging and palm oil mostly to blame. Now, it's thought that Bornean orangs may only have 1% of their original untouched habitat left by 2020. So reserves may not be the answer, or not yet. While there is corruption and their safety in the wild cannot be guaranteed, zoos remain a viable way of ensuring the future of orangutans. It's not ideal, no, far from it, but the wild situation is not ideal and something has to be done or we accept the loss of orangutans. I would rather keep some alive in zoos as a safety net, even if as yet we have no idea how we'd go about putting them back than just accept that they have no future and let them die out.
Long message, apologies, but I am trying to make the point that zoos do damn good conservation work. Don't boycptt all zoos because you are unhappy with one or two, try and put pressure on those you don't like to improve.