Bear in mind that these photos weren't spur-of-the-moment snaps. The skilled photographers who took them likely went to great effort to capture them at exactly the right moment, when the weather was dramatic, when the lighting was vivid, and when there were no people around.
Any photographer will tell you that a good photo requires timing; they probably had to get up very early, try many times, find precisely the right spot, and spend a long time waiting for the right conditions. The very best photos might have required months of perseverance.
You can do the same, but these photos show those places at their very best; don't expect them to be like this all the time.
Timing is everything
In your original post, the photos you provide were taken during the golden hour of sunrise/sunset, when the lighting is most dramatic.
Take your photo #4 (now no longer displayed) as an example:
Note how it was taken at the exact moment of sunrise (around 6am, to be specific) with an attractive arrangement of clouds, producing striking colours and contrast. The water is calm, making the lake bed beneath it visible and producing reflections of the treeline above. These things are no accident; it takes skill and patience to get it right like this.
Meanwhile, your grandparents' photo of the same scene was taken on a rather dull, overcast day in the afternoon, with choppy water and tourists getting in the way.
Moments like the one captured in this photo are ephemeral and often last only for a minute or two before the light changes, so timing is critical.
Photography vs. real life
You should also remember that while a camera captures exactly what it sees, the resulting picture is often far from what an observer would actually experience. Your senses as a human being give a far, far richer experience than a camera can ever convey (binaural hearing; smell; touch; temperature; wide-angle, high-definition, binocular HDR vision; not to mention motion), so the photographer has to compensate in some way.
Many aspects of the photo have to be carefully arranged while shooting (composition, lighting, and timing), while judicious post-production is necessary to bring out the full vividness of real life that the camera's sensor just can't capture.
For example, this photo benefits from thoughtful composition, with a rock formation providing foreground detail to balance out the distance of the rest of the photo, with the sun providing a vanishing point. The photographer has used a graduated filter (or exposure bracketing) to darken the sky (which would otherwise appear very bright) while keeping the foreground illuminated.
Also note how the reflection of the sky on the surface of the water (in the bottom-left quarter of the image) doesn't actually match the crimson hue that we see in the sky itself. This suggests that the photographer has enhanced or adjusted the colours in the sky, perhaps to better reflect what he/she saw and felt when taking the photo – something the camera couldn't do justice to.
All of these things go some way to explaining why these photos look so good beside your grandparents' photos.
In fact, Kaz has pointed out in the comments that this photo is probably a composite, with the top half (sky, horizon, treeline) shot at sunrise, and the bottom half (water, foreground) likely shot later in the day when the light was softer, for better illumination of the cove and rocks.