I'm OK with this - I would rather financially incentivize them to conserve their lands, instead of making them feel they need to monetize it to cover a tax bill.

I'd like it better if they were required to allow public access. The public is paying for this land in lost taxes, we should be able to use it.

I agree, however I think a balance needs to be struck between liability and groundskeeping, as those are currently the costs that all municipalities cover for their public parks.

Something along the lines of retaining some or most of the tax benefits for the private owner, in exchange for the municipality covering grounds maintenance, and a split between both parties for the liability insurance.

I think that’d be the start of the US developing its own “Freedom to Roam” implementation.

Think about what it means 'their land'. The people have agreed that they will protect his exclusive right to use that land. They gave him a set of rights associated with it. There are other people these days for which there was no land left - thus making a price congestion for the existing land.

Shouldn't the current owner pay the tax as means of 1) congestion pricing and 2) service fee for others guaranteeing his rights?

It feels to me like a fair tax as you pay for what you use.

So you end up with most of the land being a private park for the rich inaccessible for the rest.