If crowdfunding was like purchase of shares (which it isn't), then it wouldn't be taxable initially, but would have a capital gains tax when you sell those shares.
Most of the crowdfunding projects are in essence similar to preorders, and thus would be taxable as any other sales - if there are true donation projects, then they'd need to file for nonprofit status to be able to get tax-exempt donations.
This is why accountants are important. They know the system and paperwork and words; they know how you can pay tax in one form cheaper and later instead of expensive and now.
I don't think UK taxes lottery winnings.
though UK lottery winnings will still be taken into account for inheritance tax if the winner dies within 7 years.