I personally would not like to be a Republic, I would hate to see the likes of Tony Blair or similar bring our President, the Royal Family do give back please see below:

The Royal Family surrenders all profits from the Crown Estate—a massive property portfolio valued over £7.3 billion—to the UK Treasury, which totaled over £329 million in 2018-2019 and over £1.1 billion recently. In return, the government gives the Monarch the Sovereign Grant (approx. 12-25% of profits) to fund official duties. They also voluntarily pay income tax on private revenue.
sussexroyal.com
sussexroyal.com
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Key ways the Royal Family "gives back" include:

Surrendering Crown Estate Revenue: Profits from land, forests, and seabed (wind farms) go directly to the treasury.
Voluntary Taxes: The King and Prince of Wales voluntarily pay income tax on the revenue from the Duchy of Lancaster and Duchy of Cornwall, respectively, and other private income.

Patronages and Charity:

The family supports over 3,000 organisations, enhancing the social capital and public profile of many charities.

Diplomatic Duty:

They promote UK interests abroad, effectively acting as high-level diplomats.
www.guidelondon.org.uk
www.guidelondon.org.uk
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