Nice walkthrough. You come across a lot of these old .NET based architectures in consulting. Not just older .NET Core projects but still a lot of .NET Framework too.
It’s a hard sell to a client that they should use their budget for an upgrade to the core of their software without any visible feature additions. Hence they tend to live on in this limbo state.
Beneficial for consultants however.
This is the heart of the problem with outsourcing that the powers that be rarely recognize. Yes they might pay less by offshoring the initial development costs (CAPEX), but the long terms support and maintenance costs (OPEX) is then way more costly. It also gets harder and harder to find developers that want to work in this aging tech.