Wahed - Investment Account Vs S&S ISA?

Salaam,

I am just about to take my first step on my investing journey with Wahed Invest but I’m not 100% sure whether to open an investment account or a S&S ISA.

As far as I understand it, with an ISA you have an annual 20K allowance which allows any profits to be tax free. I guess my question is that unless you wanted to invest >20K in a single tax year is there any other benefit to choosing an investment account over the ISA?

Jazakallah