Hello!
Being consistently late to class can affect all three points that you mentioned.
It can negatively affect your grades because by being late, you are missing some content that was covered in class. By not learning the material, it will be difficult to perform well on tests, and can therefore harm your grades.
It can affect your future careers because by being late to class, you are learning that it is possible/acceptable to be late to other places. By teaching yourself to be late to class, you may bring this onto being late to work during your career.
It affects basic life skills similarly to how it affects careers. You may be habitually late to important places or functions, which is often inconvenient for yourself and inconsiderate to other people.
I hope this helps you! Have a lovely day!
- Mal