'The middle classes'? Wow. The money will support grassroots ('working class' if you must) live music venues every bit as much as the Royal Albert Hall, assuming it is distributed as intended. The arts employ hundreds of thousands of people and generate half as much as again in taxation in a year as they are being given here (and some of this is only loans). It's much-needed and exceptionally welcome support for one of the few industries left at which the UK is genuinely world-leading. It's rather more than 'looking after the middle classes'. Not saying it wouldn't be nice for a bigger chunk of cash to come zoos' ways, of course it would be, but there's no need for this sour grapes reaction to another sector getting the support it needs.
That doesn't detract from the fact that the decision makers favour the things that will benefit themselves the most.
I would say that if the Government is simply looking at the number of people employed, then this very wide 'sector' must employ far more people, that the zoo world does (or did!)...? I dont have any figures to hand so this is just an assumption. Even allowing for an equal percentage of these organisations to be as cumbersome and as overstaffed as any other sector, presumably more jobs will equal bigger grants. The value of Lego animals over real ones, is a question I could personally easily answer - but other opinion might value the plastic ones higher, I suppose. It is interesting that the UK always separates collections of living animals from collections of dead or artificial ones, in a way not done in many other countries. The zoo/museum boundary is often blurred elsewhere, but not here - even when a zoo starts to become part gallery or part museum. We are used to zoos being penalised at the expense of other 'leisure' in other UK law such as planning, so we should not be surprised if this carries over to Covid grants.
Some statistics re: the UK arts and culture sector The economic contribution of the Arts. To suggest this is just the middle-classes looking after their own seriously smacks of sour grapes. The arts and culture sector are massive economic players, and significant employers. Also, we don't yet know what the criteria will be for eligibility and payout. Much like the Zoo Fund is limited in who is eligible and how much can be applied for, there may be similar pinch points with this fund. And as @Maguari says, this fund will support more than just the big names; many, many more small, independent art and culture venues should hopefully be supported by this.
All national museums are free to enter, and have been since the mid-1990s. Prior to that time, they charged an entry fee, which was removed to allow lower-income people and families to visit. They do however charge an entry for temporary exhibitions
Note although limited in numbers Zoos are now open. Theatres may not reopen for another 12 months. 250,000 people per week normally go to West End Theatres with a huge spin off into Restaurants and Hotels etc. You can't compare an outdoor Zoo activity with a mass of people enclosed in a Theatre.
Museums are not free. Nothing in life is, unfortunately. As Pipaluk and Crowthorne said they are free to enter. All this means is that your visit is paid for by someone else (everyone else?) - ie the tax-payer.
Viaduct Animal Sanctuary - Exotic Animal Rescue, is set to close due to a lack of funds caused by the pandemic. Most animals have been moved onto other sanctuaries, or to trusted members of the public.