But you will only be able to hire the employees willing to tolerate working with it. Especially the condition of not planning any form of modernization.

And as phillipcarter noted, increasingly more libraries drop 'netstandard2.0' target, depending on the workload the performance difference is going to be anything between 50% and multiple orders of magnitude (e.g. Regex engine has gotten tens of thousands of percents faster for some patterns).

Working with .NET Framework from non-Windows environment requires using Parallels / UTM on macOS or QEMU or any other VM env. on Linux - there's Mono but it's not a replacement, and I don't think Visual Studio will work under Wine.

There are all sorts of hidden costs that you don't plan for, that come with using .NET Framework.

One of the bigger problems with staying on .NET Framework is that it limits you to C# 7.3, which lacks a lot of new language features (e.g., most pattern matching, records, nullable reference types, etc.). It can be both frustrating and even potentially career limiting to be stuck on that for too long.

You can use newer LangVersions with older targets, including .NET Framework. A good deal of features can be made work by just setting LangVersion: 13 and doing dotnet add package PolySharp. But of course this won't bring missing span-based APIs, new ASP.NET Core and EF Core, etc.

However, the workplaces that adamantly refuse to upgrade also select for developers who may not be familiar with pattern matching or other features at all, and never read release notes.

Not sure why this is so aggressively downvoted. I work in legacy software and it's true. A firm that's still on .NET Framework, PHP 5.6, or Java 8 is likely to stay on those versions for the near future.

We just moved from 4.6.1 to 4.8 this year. We maintain a frontend(++) for a major enterprise software package, and follow them. They just moved to 4.8 so we did as well. Not even the point release. The contractor I work for is pretty conservative, he likes his 1+ million dollar home and worldwide vacations. He won't be changing anything without being forced by Microsoft.

Even if Microsoft puts in a huge effort to updating a migration tool to be seamless, we wouldn't use it. It'll only happen when either the larger enterprise corporation migrates, or when Microsoft forces people off 4.8.

Writing C# code in modern .net is so much better.

It's close to the change when get/settwrs were made mostly redunant (but not quite).

Just so much less boiler plate that you didn't even really realize you were writing.

Nothing bad on staying a still supported framework.

Most of the time boring old technology beats shiny new one.

.NET as well. If you do a framework-dependent deployment, then in many cases you only need to run Windows Update, just like with .NET framework.

Yes... if you do self-contained deployments or build containers, then of course you're tied to the version you've built with - but that is your choice and therefore your responsibility.

You are now blaming having that some deployment choices cannot be updated manually. It is the wrong mindset.