Subsidies are an incredible tool when used well, like when they funded a bunch of utility cooperatives that electrified rural US. Maybe you’re asking why we should because propping up the car industry when public transit and bike infrastructure should be subsidized instead, rather than challenging subsidies, though.
Lemmy technically doesn’t hide your likes - the interface might not show you, but all your likes are public in the Fediverse. Kbin, when I used it, would show which users upvoted/downvoted a post. That’s important because it means researchers and OSI people can still do fact finding - Twitter doesn’t like the idea of having to be open even if it’s a requirement (albeit to researchers specifically) in the EU now.