Are tempered glass screen protectors ANY GOOD, when they start to crack after 1 month? going naked? 

Screen protectors are only a little bit better than the glass of the smartphone itself at preventing shattering from impacts. The main focus isn't impacts, but scratch and gash protection... If you use a case with a lip on it (your glass looks like it isn't protected by the edge of the case you use), it will keep the screen off the ground for the most part, and the protector will just have to protect from pebbles and rocks for example. Its far better for a $12-25 peice of glass to shatter or scratch when you drop it, than your phone screen itself which is up to a few hundred to replace.

protip - go to the bathroom, turn on hot shower for a few minutes to fill the room with steam, then apply the screen protector there. This will eliminate all the dust particles. Applied mine this way in November, it's still perfect today

I used the tempored glass protectors on my phones and a minimal case. The thin film ones are not wirth it. I stick with Pigen for the cases. I find that having a fan going when you are putting in the glass helps keep the dust from settling on it before you finish

My S9+ glass protector is going to turn six this September. It's almost as good as new and came as a pack of two! I suspect user error on your part. :D

Expecting German CPU

I have never used a screen protector and never had any problems

What kind of font is that you used at the beginning of this video?

I'll never forget my nokia 3310! Those were made a brick and only planned obsolescence by design.

I just use a case with a rim large enough to leave a gap between screen and the ground if it falls, have done this with all my phones for years no cracks. There are some scratches but you cant see or feel them you need to look at it under light.