Writing the same number a different way does not make it rational. There are no two natural numbers p and q so that p/q = 1 base pi.

1 is always 1. It’s 1 × b⁰ where b is the base. Anything raised to the zeroth power is 1.

10 is the base. 1 × b¹ + 0 × b⁰

Even in base π, π is still considered an irrational number; using an irrational based doesn’t change the fundamental identity of whole numbers or irrational numbers, it just changes the way we write them.

That doesn’t make it rational but simply makes it writable in 2 digits(10)

Also you should have 3.1415… “number of characters” in that base… The base becoming irrational will make the number irrational

π = 10

in base 10, 10 = 10.