Consider the following hypothetical: a country has a process in place to remove a leader from power when he has demonstrated unfitness for office. Should the predicted outcome of that process dictate whether to initiate it? I think most people would say no. In the abstract I would say if you believe he's done something impeachable then one should initiate impeachment hearings even though the result is that the senate almost definitely would not remove him from power by 2/3 vote.
But the way this entire investigation has unfolded has made it an extremely unpopular political fight. The corrupt way Trump has conducted himself doesn't trouble his supporters and Democrats probably would be less popular as a result.
I don't know the right answer. You both have good points. Maybe if this country's founders did not want the process to be political it should not take place in a political branch! It's like we've had a nationwide referendum on corruption and the result is that it's okay if you knew your guy was corrupt when you voted for him.