As a FLOSS supporter, I have been perturbed they charge money and let Thunderbird languish, just like I have been as an individual user all these years. Problem

As a FLOSS supporter, I have been perturbed they charge money and let Thunderbird languish, just like I have been as an individual user all these years. Problem is I don't make a profit off it. Do they give back? I would like to stand corrected if I arrogantly assumed.