What makes you think bombing in that video was indiscriminate? On the opposite, I see single buildings being destroyed, while the neighbouring buildings stay intact. That's a very precise strike by any standard. Furthermore, there is nothing to convince me these buildings were not occupied by Hamas terrorists (which are known to hide behind civilian population).

https://www.youtube.com/watch?v=70Oqo_wmuGo

https://www.youtube.com/watch?v=g0wJXf2nt4Y

https://www.youtube.com/watch?v=fcrWy3PT6zc

https://www.youtube.com/watch?v=PPU4UN03t7E

And yes, I agree with you that knocking on the roof is a very considerate "last warning". Which other country goes to such lengths to minimize civilian loss of life? There are early warnings, too, though: by phone, text and leaflets. That's why you don't see any people running out of that house: it is already empty.