I think you are asking what the benefits are? The main benefit is that we can trust what these systems are doing better. Or we can self host them. If we just take the weights, then it is unclear how these systems might be lying to us or manipulating us.

Another benefit is that we can learn from how the training and other steps actually work. We can change them to suit our needs (although costs are impractical today). Etc. It’s all the usual open source benefits.