Less contrived examples are:
2. Goodstein's Theorem https://en.wikipedia.org/wiki/Goodstein%27s_theorem
3. A theorem stating that every computable strategy is a winning strategy in the hydra game (see https://faculty.baruch.cuny.edu/lkirby/accessible_independen...)
4. The strengthened finite Ramsey theorem, see https://en.wikipedia.org/wiki/Paris%E2%80%93Harrington_theor...