The degrees in vertical and horizontal direction are about 1.5 times different in the given area (center of Europe). This depends on latitude, in equator they are equal (lat=long), but in another extreme, near poles they will be very off as longitude in real pole will be 0 meters. Think a bit how longitudes and latitudes work really on globe. So this buffering "hack" with lat/long creates exactly this issue - with horizontal line buffer will be much wider than with vertical one, and with diagonal places you would get some average and you may not even notice it. So if you need better accuracy then you cannot use this suggested code/method.
The degrees in vertical and horizontal direction are about 1.5 times different in the given area (center of Europe). This depends on latitude, in equator they are equal (lat=long), but in another extreme, near poles they will be very off as longitude in real pole will be 0 meters. Think a bit how longitudes and latitudes work really on globe. So this buffering "hack" with lat/long creates exactly this issue - with horizontal line buffer will be much wider than with vertical one, and with diagonal places you would get some average and you may not even notice it. So if you need better accuracy then you cannot use this suggested code/method.