If anyone is interested in using C# on a FPGA to learn take a look at https://hastlayer.com/project
The model is just too different for these things to make sense 99% of the time. It's like trying to run general purpose code on a GPU, but even worse.
"...The input of Hastlayer can be a program written in dozens of programming languages (including several of the most popular ones as C#, C++, Python, PHP..."
Typical programming languages run code one line at a time from the top to the bottom, occasionally calling functions or looping.
FPGA's instead have code which specifies a kind of circuit diagram of what is connected to what.
You can make something to translate one to the other, but by translating a programming language to a circuit diagram you usually end up bits of creating circuitry for each line of code, and then extra circuitry which makes each bit be activated in sequence.
That typically leaves 99.9% of the circuitry unused (deactivated) at any point in time. FPGA's don't have much space for circuitry, so by translating a program from C to an FPGA directly you'll usually end up with a huge design with a very low throughput, since the vast majority of the circuit is sitting idle most of the time.
Real FPGA designs will typically aim to use circuitry very sparingly, and keep as much of it in use as possible all the time to get maximal performance. Complex, sequential and non-performance critical tasks are typically not a good fit for an FPGA and are usually offloaded to a programmable processor instead.
The more useful way to write hardware using programming languages is to create a model of hardware and then use the language features to manipulate that model, and use it to create abstractions for actual hardware patterns.