Algorithmic patents amount to patenting maths which, by very longstanding precedence, is not a thing, for good reason.

You absolutely can patent "math" (well, more like physics) IRL. What matters though is that the invention actually has to be novel and non-obvious, and IMO it should also be harder to patent if it's in a segment like software where costs of development, iteration and "research" are generally extremely cheap. Like, it should have a way higher bar for the "novelness".

And I would not allow any kind of software design patent (use copyright or trademark to protect that).