I didn't say there's nobody left to push updates. I'm talking about the lead devs and leadership who are fleeing following the collapse of the underlying crypto. If you'd like to see a specific breakdown of Session (as well as other private messengers), and it's various attributes, I suggest checking out

SecuChart - interactive secure messenger feature comparison

Chat app filters and adaptive colored property difference highlighting all work using CSS-only without JS. Contributions welcome!

It illuminates the platform's shortcomings (and benefits) in comparison with others. In terms of privacy, the most significant flaw (self-imposed) is the removal of perfect forward secrecy. And there are a handful of other significant concerns that are outlined. Again, there's no good reason to continue using Session given the facts, and the availability of superior options.