The foxes are great proof that behaviour has a genetic component. But the change in behaviour over the course of Belyaev's experiments does not seem that remarkable. Some foxes of the initial population were already happy to approach humans and be held by them, before the experiment even started. The pictures in [1] show farm foxes from Prince Edward Island in 1922 which seem to behave extremely similar to the foxes in the youtube video you linked to.
You are basically claiming that the difference in behaviour that was reported between the initial population and later generations was exaggerated because there seems to be a photo from 1922 showing a tame individual. I hope you see how claiming any level of tameness based on a few photos cannot be considered good evidence. Photos can be highly misleading, it's easy to see something that's not there. From what I understand, all sources reporting from this experiment and other similar ones claim huge differences in behaviour not only betweeen the initial generation and the selected ones, but also between control groups of animals which were kept in very similar conditions, except they were not submitted to "tameness selection". This difference of course over a large amount of animals, not over just a few. So, maybe the animals in the photo were indeed fairly tame (which as I said before, cannot be concluded from old photos), but even then, that does not mean that they were nearly as common as in the "evolved" animals from the study, where the rate of highly tamed individuals reached above 80% already. Which means that pointing out a counter-example is like claiming global warming is fake because it's been cold in the Midwest.
It is almost impossible to show how tame the fur farm foxes on Prince Edward Island really were, but in addition to the photos - of which there are more than one [1] - there are also written reports about how tame the foxes where [2]:
"Dr. Frank, among other things at Montreal, had a pair of tame foxes lead about on the main streets, driven around in automobiles and taken to a public dance, where the girls did the fox trot with these foxes around their necks, and all this was photographed, moving pictures taken, etc., and to cap the climax Dr. Frank hired two airplanes, took up a pair of foxes in one and from the other airplane a photograph ground out several reels to be shown in the movies in the near future."
How common these traits were is another difficult question. But given that there was prior selection for tameness and that Belyaev specifically looked for those tame foxes to include in his experiment [3], it does not seem so surprising that this trait very quickly became more common.
[1] https://doi.org/10.1016/j.tree.2019.10.011