Having developed a significant amount of perfect precision math libs over the years, rationals do explode for lots of common computations. That is the main reason they are not standard in all computing. They also cannot represent a lot of desired results.

The problem is rational number performance slows exponentially (or uses large amounts of RAM) for many common uses, which will kill scripts, unless they suddenly fix precision (i.e., no longer exact) or change to float (also a surprise for people).

Setting them as floats has the odd numerical issue, which is not that bad, but doesn't require a host of other mitigations to prevent other bad surprises.

For example, summing 1/n^2 for n=1 to 100000 as floats runs quickly and is very close to the exact answer. As rationals the numerator and denominator require working with 86000 digit numbers.

Also, does raku still do this?

say (1/6+1/6).raku #<1/3>

say (1/10+1/10).raku #0.2

That seems surprising, does it not?