In my side of things (wildlife) there is a lot of skill involved and frankly people have to invest a lot of time to get there. For example hand rearing birds, the syringe feeding is hard and delicate, you can't speak to them etc. So most of our volunteers that are only coming once a month end up doing unskilled work, that frankly is less rewarding.
People tend to want to spend time with the animals, but really it's stuff like cleaning out, admin and washing up that need doing, but people don't want to do that.
I volunteer every other Sunday for a wildlife charity. I've been doing this for 6 years now. I work full time Mon - Fri (approx 50-60+ hours/week) in a stressful, high pressure job and my volunteering with wildlife is my way of having some 'me time'. But it means a 100 mile drive so expensive with current petrol prices, and Sunday traffic can mean I spend 3-4 hours total in my car, on top of my actual volunteering shift. It's exhausting! I used to do it weekly but had to cut back to fortnightly because it was just too tiring for me (I also have long Covid) and was affecting my 'day job' . It is incredibly rewarding spending time with the animals but it's taken time to build the experience to do that. I've spent a lot of time cleaning up poo and pee and doing washing (and still do).
Because of my existing wildlife experience, I was also asked to cover one summer as a volunteer baby bird feeder. OMG it was stressful! It's surprisingly complex. Rewarding but absolutely terrifying that some tiny little baby bird is going to die because you made a mistake.
I've been volunteering on and off since childhood. My family have always got involved with helping the local community so it's always just been normal to me. I was one of those annoying kids at age 7 selling stuff on a table at the side of the road to raise money for the RSPCA. 🙄I've been a volunteer vet's assistant at the PDSA, I've been a Samaritan, I've delivered project management training courses to charity workers, and only a week ago a group of us spent a day (very badly) gardening at a children's adventure playground in Hackney.
I wish I could do more. A lot more. But my job is very full-on so I have to be realistic about what's possible. I had to give up Samaritans because of work - their mandatory shift timings clashed with my job and in the end I just couldn't make it work on a regular basis (although I believe the Samaritans have relaxed their shift requirements in recent years).