Only reason that I see is that is free to use, why other alternatives are either paid or you needs to be hosted (and thus you need to pay the cost of a server and the work to maintain it).

Free means it's not yours, and could disappear or change at any time.

If you are a small software company, presumably your code is your most important asset. You should be self-hosting that, then you can know exactly where it is and whether it's actually backed up and you can instantly talk to the person who is responsible for it.

If you can't afford 5-10 dollars/month for a cheap vps, you have no business setting up a company.