There is a very large contingency of older people who volunteer-much of the social infrastructure of the country would grind to a stop without them .
I was talking to a Community Furniture group run by a north-east council. They pay three staff and have 25-30 volunteers (part-time doing varying amounts but all making a commitment) who go out on vans collecting the furniture, load it up, take it back to the depot, clean it up, run the warehouse, take the phone calls , book the collections, arrange deliveries. Plus they get staff on 'work experience' from the 'unemployment office'. They are mainly people 50+. Some are late 60s/early 70s.
The heritage centre I volunteer at has about 30 volunteers and 2 full time paid staff and 2 part-time paid centre staff plus a part-time paid cleaner 2 hrs a day. It includes a cafe, exhibition space, gallery , small shop and events space. Volunteers range between late 30s to late 70s. They serve in the cafe, shop, have an exhibitions team, run walks, talks, classes, raise funds, run reception, do the admin. No doubt but that it would close without them.
FIL has created a really robust refugee support project at the church he and MIL go to. It is entirely staffed and run by volunteers- it offers benefits advice, social support- drop-in mornings/afternoons where coffee and cake or lunch is available, a playgroup (MIL does this😁), clothing (they are always collecting clothing, washing it, DH's 90+ grandma mends things), access to interpreters, advocacy support , help with furniture needs. All done by volunteers mainly aged 55+, a couple of younger women.
I do some bird warden stuff through an environmental charity and it is astonishing what a group of local people have organised. There are groups like this all over the country who spend many hours weekly monitoring wildlife numbers, creating and protecting habitats for them, looking after injured creatures. Again they are mainly older people (probably 40+ mainly). Locally we have a species group doing staggering work with one rapidly declining bird species- self set-up, self-funded, low-key and I'd say all of them are 65+.