As several have said, Autumn, J52, Jax and Witzend, Chelsea does get crowded beyond belief (just see the masses when the BBC coverage is on their raised platform!).
I went once, it's a hot, crowded, expensive day, and I wouldn't go again, but the best advice (I gather) is to get there as the gates open (so, as the crack of dawn goes out of earshot?!) and get round while you can still see things without a football crowd in the way -- and when I went, bouncers shoving you past stalls to get a move on and ease the queues!
For those blaming the BBC for price rises, that is SUCH an ill-informed attack! The RHS governs prices, and sadly they saw that the whole shebang gets a massive attendance, and moved the prices as per market forces. Given that squillions are STILL willing to pay very silly money, AND endure conditions that prisoner welfare groups would likely complain about, I doubt that they'll be reducing those prices anytime soon?!!
Some have mentioned other shows that are likely better value, and more room to move?! In the past, when on holiday up there, we've visited Harrogate, and Tatton Park, also Shrewsbury -- though I think that one has bitten the dust ("rocketing costs"), shame, as it's a nice town to visit.
A quick Google/AI search suggested alternative shows at Harrogate, Tatton (next is 2027), Hampton Court (ditto), Sandringham, Windsor and Badminton, with a little mention of Arley Hall (?), and Wentworth Woodhouse (never heard of it before!). Also I see a mention of Malvern, Blenheim Palace (careful, traffic is bonkers!), and Southport.
However, that famous new AI tool belied the 'I' part of the name, as it put up Shrewsbury, which is NOT running this year, and may struggle to return, it seems, they'd need to raise prices and upset people, to cover costs!