Ditto, years ago I never really understood the hype about ISAs - partly through only being exposed to cash ISAs. How do you get rich from saving tax on 20,000 per year (if you can even afford that)?
I now realise it’s the compounding that’s also protected. If your 20,000 multi-bags like a Shopify or an Ocado, then you could cash out and have £100,000 in your ISA tax-free to reinvest within the same wrapper.
This is why my LISA is full of risky AIM stocks - £4000 a year won’t get me a house even with bonus but a 10-bagger would cover the losses and vastly expand the wrapper.