A lot of this really depends on the game you're trying to play.
With emulated games, it's trivial to render at low resolutions and scale them to fit the display with crisp pixels.
For older PC games your options may be more limited. If it's a very old game you might find that API wrappers such as dgVoodoo2 support crisp scaling.
If it's a newer game which can support high resolution rendering, it may be possible to use a ReShade shader to give it a low resolution appearance.
Just a DVI to VGA adaptor and you're good to go.
DVI is dead. New GPUs are not supposed to use it any more, and if AIBs use one, it's a DVI-D port replacing an HDMI port rather than DVI-I.
Unfortunately, modern screen tech is all fixed-pixel with scaling. It's really not how things should have evolved if gaming were given more consideration by TV manufacturers about 2 decades ago.
I'm not sure what the alternative would be to fixed-pixel displays, other than continuing to produce CRTs - and that was never going to happen.
But fixed-pixel displays are not really the problem - it's the scaling which is used, and the lack of options.
This is why I campaigned to NVIDIA for five years to try and get them to implement integer scaling. Ironically now that it is, I don't have a GPU that supports the feature to even test it.
And there are better options now too.
You can use nearest neighbor (sharp) scaling to the closest integer, and use linear filtering for the last fraction required to fill the display or correct the aspect ratio.
There are now shaders that do an even better job than that, which can be used in emulators.
There was some discussion of it in this topic recently:
Yeah not gunna mess with all that.i was hoping for a click a button solution. PS5 better have all this stuff included for PS1 emulation
Unfortunately the only "one click" solution is the integer scaling option in the NVIDIA driver if you have an RTX card (or 1660?).
It's frustrating that display manufacturers don't have a good scaling solution for pixel art/low resolution games built in. It shouldn't even be difficult to implement. The problem is convincing them to do it.