This question cannot be answered directly because there are many different target groups and desires.

There are programs from thousands of euros a month to free programs, and everything in between.
You can check out that artificial intelligence in the cloud that artificially enhances (or even replaces) your photos can’t be run for free.

I also believe in “nothing is free” and sometimes wonder what the revenue model is for “free” cloud tools for this.

There is a free tool that runs locally and whose source code is also on GitHub:
https://github.com/k4yt3x/video2x

For anything else I would say just use Google. I don’t want to advertise here a lot of paid tools when there are so many good alternatives.

I myself use a tool that costs quite a bit (consumer price range), but I’ve really achieved great things with it.

For example, I have a wedding video of my grandparents that was recorded in 1954.
– Increase the image to 4K
– Stuttering image upscaling to 60fps
– Filter out white noise and age lines
– Artificially color the pictures fairly correctly.

These tools still have a lot to offer in this regard, and I suspect they will be able to do more in the future than they already do.